1
 
                                                                    EXHIBIT 99.1
- --------------------------------------------------------------------------------
           THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., CENTRAL TIME,
     ON                     , 1999 UNLESS EXTENDED (THE "EXPIRATION DATE").
- --------------------------------------------------------------------------------
 
                             LETTER OF TRANSMITTAL
                               OFFER TO EXCHANGE
 
                    10% SENIOR SUBORDINATED NOTES DUE 2009,
          WHICH HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,
                          FOR ANY AND ALL OUTSTANDING
                     10% SENIOR SUBORDINATED NOTES DUE 2009
                                       OF
 
                             OGLEBAY NORTON COMPANY
 
                                  Deliver to:
                  NORWEST BANK MINNESOTA, NATIONAL ASSOCIATION
 

                                                                    
By Registered or Certified Mail:  By Hand Delivery or Overnight Courier:          In Person:
 
    Norwest Bank Minnesota,              Norwest Bank Minnesota,           Norwest Bank Minnesota,
      National Association                 National Association              National Association
   Corporate Trust Operations           Corporate Trust Operations           Northstar East Bldg.
         P.O. Box 1517                        Norwest Center                   608 2nd Ave. S.
   Minneapolis, MN 55480-1517              Sixth and Marquette                    12th Floor
                                        Minneapolis, MN 55479-0113         Corporate Trust Services
                                                                          Minneapolis, MN 55479-0113

 
                                 By Facsimile:
 
                                 (612) 667-4927
 
                              Confirm By Telephone
 
                                 (612) 667-9764
 
     Your delivery of this letter of transmittal will not be valid unless you
deliver it to one of the addresses, or transmit it to the facsimile number, set
forth above. Please carefully read this entire document, including the
instructions, before completing this letter of transmittal. DO NOT DELIVER THIS
LETTER OF TRANSMITTAL TO OGLEBAY NORTON.
 
     By completing this letter of transmittal, you acknowledge that you have
received and reviewed Oglebay Norton's prospectus dated                     ,
1999 and this letter of transmittal, which together constitute the "Exchange
Offer." This letter of transmittal and the prospectus have been delivered to you
in connection with Oglebay Norton's offer to exchange its 10% Senior
Subordinated Notes due 2009, which have been registered under the Securities Act
(the "Exchange Notes") for its outstanding 10% Senior Subordinated Notes due
2009 (the "Outstanding Notes"). $100,000,000 in principal amount of the
Outstanding Notes are currently issued and outstanding.
 
     This letter of transmittal is to be completed by Holder (this term is
defined below) of Outstanding Notes if:
 
          (1) the Holder is delivering certificates for Outstanding Notes with
     this document, or
 
          (2) the tender of certificates for Outstanding Notes will be made by
     book-entry transfer to the account maintained by Norwest Bank Minnesota,
     National Association, the exchange agent for these notes, at the Depository
     Trust Company ("DTC") according to the procedures described in the
     prospectus under the heading "VI.F. The Exchange Offer -- Procedures for
     Tendering." Please note that delivery of documents required by this letter
     of transmittal to DTC does not constitute delivery to the exchange agent.
   2
 
     You must tender your Outstanding Notes according to the guaranteed delivery
procedures described in this document if:
 
          (1) your Outstanding Notes are not immediately available;
 
          (2) you cannot deliver your Outstanding Notes, this letter of
     transmittal and all required documents to the exchange agent before on or
     before the Expiration Date; or
 
          (3) you are unable to obtain confirmation of a book-entry tender of
     your Outstanding Notes into the exchange agent's account at DTC on or
     before the Expiration Date.
 
     More complete information about guaranteed delivery procedures is contained
in the prospectus under the heading "VI.H. The Exchange Offer -- Guaranteed
Delivery Procedures." You should also read Instruction 1 to determine whether or
not this section applies to you.
 
     As used in this letter of transmittal, the term "Holder" means (1) any
person in whose name Outstanding Notes are registered on the books of Oglebay
Norton, (2) any other person who has obtained a properly executed bond power
from the registered Holder or (3) any person whose Outstanding Notes are held of
record by DTC who desires to deliver such notes by book-entry transfer at DTC.
You should use this letter of transmittal to indicate whether or not you would
like to participate in the Exchange Offer. If you decide to tender your
Outstanding Notes, you must complete this entire letter of transmittal.
 
     YOU MUST FOLLOW THE INSTRUCTIONS IN THIS LETTER OF TRANSMITTAL -- PLEASE
READ THIS ENTIRE DOCUMENT CAREFULLY. IF YOU HAVE QUESTIONS OR NEED HELP, OR IF
YOU WOULD LIKE ADDITIONAL COPIES OF THE PROSPECTUS AND THIS LETTER OF
TRANSMITTAL, YOU SHOULD CONTACT THE EXCHANGE AGENT AT (612) 667-9764 OR AT ITS
ADDRESS SET FORTH ABOVE.
 
     Please describe your Outstanding Notes below.
 

                                                                        
- -----------------------------------------------------------------------------------------------------------
                                     DESCRIPTION OF OUTSTANDING NOTES
- -----------------------------------------------------------------------------------------------------------
                                                         AGGREGATE PRINCIPAL
 NAME(S) AND ADDRESS(ES)                                      AMOUNT OF
 OF REGISTERED HOLDER(S)                                  OUTSTANDING NOTES           PRINCIPAL AMOUNT
   (PLEASE COMPLETE, IF                                     REPRESENTED BY             OF OUTSTANDING
          BLANK)             CERTIFICATE NUMBER(S)          CERTIFICATE(S)            NOTES TENDERED*
- -----------------------------------------------------------------------------------------------------------
 
                           --------------------------------------------------------------------------------
 
                           --------------------------------------------------------------------------------
 
                           --------------------------------------------------------------------------------
 
                           --------------------------------------------------------------------------------
 
                                                      TOTAL
- -----------------------------------------------------------------------------------------------------------

 
* You will be deemed to have tendered the entire principal amount of Outstanding
  Notes represented in the column labeled "Aggregate Principal Amount of
  Outstanding Notes Represented by Certificate(s)" unless you indicate otherwise
  in the column labeled "Principal Amount of Outstanding Notes Tendered."
 
     If you need more space, list the certificate numbers and principal amount
of Outstanding Notes on a separate schedule, sign the schedule and attach it to
this letter of transmittal.
 
[ ] CHECK HERE IF YOU HAVE ENCLOSED OUTSTANDING NOTES WITH THIS LETTER OF
    TRANSMITTAL.
 
[ ] CHECK HERE IF YOU WILL BE TENDERING OUTSTANDING NOTES BY BOOK-ENTRY TRANSFER
    MADE TO THE EXCHANGE AGENT'S ACCOUNT AT DTC
 
     COMPLETE THE FOLLOWING ONLY IF YOU ARE AN ELIGIBLE INSTITUTION (THIS TERM
IS DEFINED BELOW):
 
                                        2
   3
 
Name of Tendering Institution:
- --------------------------------------------------------------------------------
 
Account Number:
- --------------------------------------------------------------------------------
 
Transaction Code Number:
- --------------------------------------------------------------------------------
 
[ ] CHECK HERE IF YOU ARE DELIVERING TENDERED OUTSTANDING NOTES THROUGH A NOTICE
    OF GUARANTEED DELIVERY AND HAVE ENCLOSED THAT NOTICE WITH THIS LETTER OF
    TRANSMITTAL
 
COMPLETE THE FOLLOWING ONLY IF YOU ARE AN ELIGIBLE INSTITUTION:
 
Name(s) of Registered Holder(s) of Outstanding Notes:
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
Date of Execution of Notice of Guaranteed Delivery:
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
Window Ticket Number (if available):
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
Name of Institution that Guaranteed Delivery:
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
 
Account Number (if delivered by book-entry transfer):
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                         SPECIAL ISSUANCE INSTRUCTIONS
                         (SEE INSTRUCTIONS 4, 5 AND 6)
 
  Complete this section ONLY if: (1) certificates for untendered Outstanding
Notes are to be issued in the name of someone other than you; (2) certificates
for Exchange Notes issued in exchange for tendered and accepted Outstanding
Notes are to be issued in the name of someone other than you; or (3) Outstanding
Notes tendered by book-entry transfer that are not exchanged are to be returned
by credit to an account maintained at DTC.
 
Issue Certificate(s) to:
 
Name
- ------------------------------------------------------
                     (PLEASE PRINT)
 
Address
- ------------------------------------------------------
 
- ------------------------------------------------------
 
- ------------------------------------------------------
                  (INCLUDE ZIP CODE)

- ------------------------------------------------------
 (TAXPAYER IDENTIFICATION OR SOCIAL SECURITY NUMBER)
     (PLEASE ALSO COMPLETE SUBSTITUTE FORM W-9)

 
                         SPECIAL DELIVERY INSTRUCTIONS
                         (SEE INSTRUCTIONS 4, 5 AND 6)
 
  Complete this section ONLY if certificates for untendered Outstanding Notes,
or Exchange Notes issued in exchange for tendered and accepted Outstanding Notes
are to be sent to someone other than you, or to you at an address other than the
address shown above.
 
Mail and deliver Certificate(s) to:
 
Name
- ------------------------------------------------------
                     (PLEASE PRINT)
 
Address
- ------------------------------------------------------
 
- ------------------------------------------------------
 
- ------------------------------------------------------
                  (INCLUDE ZIP CODE)

- ------------------------------------------------------

 
                                        3
   4
 
Ladies and Gentlemen:
 
     According to the terms and conditions of the Exchange Offer, I hereby
tender to Oglebay Norton the principal amount of Outstanding Notes indicated
above. At the time these notes are accepted by Oglebay Norton, and exchanged for
the same principal amount of Exchange Notes, I will sell, assign, and transfer
to Oglebay Norton all right, title and interest in and to the Outstanding Notes
I have tendered. I am aware that the exchange agent also acts as the agent of
Oglebay Norton. By executing this document, I irrevocably appoint the exchange
agent as my agent and attorney-in-fact for the tendered Outstanding Notes with
full power of substitution to:
 
          1.  deliver certificates for the Outstanding Notes, or transfer
     ownership of the Outstanding Notes on the account books maintained by DTC,
     to Oglebay Norton and deliver all accompanying evidences of transfer and
     authenticity to Oglebay Norton, and
 
          2.  present the Outstanding Notes for transfer on the books of Oglebay
     Norton, receive all benefits and exercise all rights of beneficial
     ownership of these Outstanding Notes, according to the terms of the
     Exchange Offer. The power of attorney granted in this paragraph is
     irrevocable and coupled with an interest.
 
     I represent and warrant that I have full power and authority to tender,
sell, assign, and transfer the Outstanding Notes that I am tendering. I
represent and warrant that Oglebay Norton will acquire good and unencumbered
title to the Outstanding Notes, free and clear of all liens, restrictions,
charges and encumbrances and that the Outstanding Notes will not be subject to
any adverse claim at the time Oglebay Norton acquires them. I further represent
that:
 
          1.  any Exchange Notes I will acquire in exchange for the Outstanding
     Notes I have tendered will be acquired in the ordinary course of business;
 
          2.  I have not engaged in, do not intend to engage in, and have no
     arrangement with any person to engage in, a distribution of any Exchange
     Notes issued to me; and
 
          3.  I am not an "affiliate" (as defined in Rule 405 under the
     Securities Act) of Oglebay Norton.
 
     I understand that the Exchange Offer is being made in reliance on
interpretations contained in letters issued to third parties by the staff of the
Securities and Exchange Commission ("Commission"). These letters provide that
the Exchange Notes issued in exchange for the Outstanding Notes in the Exchange
Offer may be offered for resale, resold, and otherwise transferred by a Holder
of Exchange Notes, unless that person is an "affiliate" of Oglebay Norton within
the meaning of Rule 405 under the Securities Act, without compliance with the
registration and prospectus delivery provisions of the Securities Act. The
Exchange Notes must be acquired in the ordinary course of the Holder's business
and the Holder must not be engaging in, must not intend to engage in, and must
not have any arrangement or understanding with any person to participate in, a
distribution of the Exchange Notes.
 
     If I am a broker-dealer that will receive Exchange Notes for my own account
in exchange for Outstanding Notes that were acquired as a result of
market-making activities or other trading activities (a "Participating
Broker-Dealer"), I acknowledge that I will deliver a prospectus in connection
with any resale of the Exchange Notes. However, by this acknowledgment and by
delivering a prospectus, I will not be deemed to admit that I am an
"underwriter" within the meaning of the Securities Act. If I am a Participating
Broker-Dealer, I will, on a weekly basis during the 90-day period following the
Expiration Date, or any longer period required if use of the prospectus has been
suspended by Oglebay Norton, contact Oglebay Norton's Investor Relations
Department at (216) 861-3300 to confirm the availability of the prospectus for
delivery in connection with resales.
 
     Upon request, I will execute and deliver any additional documents deemed by
the exchange agent or Oglebay Norton to be necessary or desirable to complete
the assignment, transfer, and purchase of the Outstanding Notes I have tendered.
 
                                        4
   5
 
     I understand that Oglebay Norton will be deemed to have accepted validly
tendered Outstanding Notes when Oglebay Norton gives oral or written notice of
acceptance to the exchange agent.
 
     If, for any reason, any tendered Outstanding Notes are not accepted for
exchange in the Exchange Offer, certificates for those unaccepted Outstanding
Notes will be returned to me without charge at the address shown below or at a
different address if one is listed under "Special Delivery Instructions." Any
unaccepted Outstanding Notes which had been tendered by book-entry transfer will
be credited to an account at DTC, as soon as reasonably possible after the
Expiration Date.
 
     All authority granted or agreed to be granted by this letter of transmittal
will survive my death, incapacity or, if I am a corporation or institution, my
dissolution and every obligation under this letter of transmittal is binding
upon my heirs, personal representatives, successors, and assigns.
 
     I understand that tenders of Outstanding Notes according to the procedures
described in the prospectus under the heading "VI.F. The Exchange
Offer -- Procedures for Tendering" and in the instructions included in this
document constitute a binding agreement between myself and Oglebay Norton
subject to the terms and conditions of the Exchange Offer.
 
     Unless I have described other instructions in this letter of transmittal
under the section "Special Issuance Instructions," please issue the certificates
representing Exchange Notes issued and accepted in exchange for my tendered and
accepted Outstanding Notes in my name, and issue any replacement certificates
for Outstanding Notes not tendered or not exchanged in my name. Similarly,
unless I have instructed otherwise under the section "Special Delivery
Instructions," please send the certificates representing the Exchange Notes
issued in exchange for tendered and accepted Outstanding Notes and any
certificates for Outstanding Notes that were not tendered or not exchanged, as
well as any accompanying documents, to me at the address shown below my
signature. If both "Special Payment Instructions" and "Special Delivery
Instructions" are completed, please issue the certificates representing the
Exchange Notes issued in exchange for my tendered and accepted Outstanding Notes
in the name(s) of, and return any Outstanding Notes that were not tendered or
exchanged and send such certificates to, the person(s) so indicated. I
understand that if Oglebay Norton does not accept any of the tendered
Outstanding Notes for exchange, Oglebay Norton has no obligation to transfer any
Outstanding Notes from the name of the registered Holder(s) according to my
instructions in the "Special Payment Instructions" and "Special Delivery
Instructions" sections of this document.
 
                                        5
   6
 
                        PLEASE SIGN HERE WHETHER OR NOT
             OUTSTANDING NOTES ARE BEING PHYSICALLY TENDERED HEREBY
 

                                               
- ------------------------------------------------  ------------------------------------------------
                                                  (Date)
 
- ------------------------------------------------  ------------------------------------------------
Signature(s) of Registered Holder(s)              (Date)
or Authorized Signatory
 
Area Code and Telephone Number(s):
- --------------------------------------------------------------------------------------------------
 
Tax Identification or Social Security Number(s):
- --------------------------------------------------------------------------------------------------

 
     The above lines must be signed by the registered Holder(s) of Outstanding
Notes as their name(s) appear(s) on the certificate for the Outstanding Notes or
by person(s) authorized to become registered Holders(s) by a properly completed
bond power from the registered Holder(s). A copy of the completed bond power
must be delivered with this letter of transmittal. If any Outstanding Notes
tendered through this letter of transmittal are held of record by two or more
joint Holders, then all such Holders must sign this letter of transmittal. If
the signature is by trustee, executor, administrator, guardian,
attorney-in-fact, officer of a corporation or other person acting in a fiduciary
or representative capacity, then such person must (1) state his or her full
title below and (2) unless waived by Oglebay Norton, submit evidence
satisfactory to Oglebay Norton of such person's authority to act on behalf of
the Holder. See Instruction 4 for more information about completing this letter
of transmittal.
 

        
Name(s):
           ------------------------------------------------------------
 
           ------------------------------------------------------------
                                  (Please Print)
Capacity:
           ------------------------------------------------------------
Address:
           ------------------------------------------------------------
 
           ------------------------------------------------------------
                                (Include Zip Code)
 
           Signature(s) Guaranteed by an Eligible Institution, if
           required by Instruction 4:
 
           ------------------------------------------------------------
                              (Authorized Signature)
 
           ------------------------------------------------------------
                                     (Title)
 
           ------------------------------------------------------------
                                  (Name of Firm)

 
Dated
- ------------------------ , 1999
 
                                        7
   7
 
                   PLEASE COMPLETE SUBSTITUTE FORM W-9 BELOW.
 
          PAYOR'S NAME:  NORWEST BANK MINNESOTA, NATIONAL ASSOCIATION
 

                                                                                   
- ------------------------------------------------------------------------------------------------------------------------
 
                                  PART 1--PLEASE PROVIDE YOUR TIN IN THE BOX AT RIGHT     ----------------------------
  SUBSTITUTE                      AND CERTIFY BY SIGNING AND DATING BELOW.                   SOCIAL SECURITY NUMBER
   FORM W-9
                                                                                                       OR
                                                                                          ----------------------------
                                                                                         EMPLOYER IDENTIFICATION NUMBER
                                ----------------------------------------------------------------------------------------
  DEPARTMENT OF THE TREASURY
  INTERNAL REVENUE SERVICE        PART 2 -- CERTIFICATION -- UNDER PENALTIES OF                     PART 3 --
                                  PERJURY, I CERTIFY THAT:                                      AWAITING TIN [ ]
                                  (1) THE NUMBER SHOWN ON THIS FORM IS MY CORRECT TIN
                                      (OR I AM WAITING FOR A NUMBER TO BE ISSUED TO ME)
                                      AND
                                  (2) I AM NOT SUBJECT TO BACKUP WITHHOLDING BECAUSE
                                      (A) I AM EXEMPT FROM BACKUP WITHHOLDING, OR (B) I
                                      HAVE NOT BEEN NOTIFIED BY THE INTERNAL REVENUE
                                      SERVICE ("IRS") THAT I AM SUBJECT TO BACKUP
                                      WITHHOLDING AS A RESULT OF FAILURE TO REPORT ALL
                                      INTEREST OR DIVIDENDS, OR (C) THE IRS HAS
                                      NOTIFIED ME THAT I AM NO LONGER SUBJECT TO BACKUP
                                      WITHHOLDING.
                                ----------------------------------------------------------------------------------------

 

                                                                               
                                     CERTIFICATION INSTRUCTIONS -- YOU MUST CROSS OUT ITEM (2) IN THE BOX ABOVE IF YOU
  PAYER'S REQUEST FOR                HAVE BEEN NOTIFIED BY THE IRS THAT YOU ARE CURRENTLY SUBJECT TO BACKUP WITHHOLDING
  TAXPAYER IDENTIFICATION            BECAUSE OF UNDERREPORTING INTEREST OR DIVIDENDS ON YOUR TAX RETURN.
  NUMBER ("TIN")
  CERTIFICATION                      SIGNATURE __________  DATE __________ , 1998
- -----------------------------------------------------------------------------------------------------------------------

 
NOTE: IF YOU DO NOT COMPLETE AND RETURN THIS FORM YOU MAY BE SUBJECT TO BACKUP
      WITHHOLDING OF 31% OF PAYMENTS MADE TO YOU UNDER THIS EXCHANGE OFFER. FOR
      MORE INFORMATION, PLEASE REVIEW THE ENCLOSED GUIDELINES FOR CERTIFICATION
      OF TAXPAYER IDENTIFICATION NUMBER ON SUBSTITUTE FORM W-9.
 

                                                                                                             
- -----------------------------------------------------------------------------------------------------------------------
                                CERTIFICATE OF AWAITING TAXPAYER IDENTIFICATION NUMBER
     I CERTIFY UNDER PENALTIES OF PERJURY THAT A TAXPAYER IDENTIFICATION NUMBER HAS NOT BEEN ISSUED TO ME, AND
     EITHER (A) I HAVE MAILED OR DELIVERED AN APPLICATION TO RECEIVE A TAXPAYER IDENTIFICATION NUMBER TO THE
     APPROPRIATE INTERNAL REVENUE CENTER OR SOCIAL SECURITY ADMINISTRATION OFFICE OR (B) I INTEND TO MAIL OR
     DELIVER AN APPLICATION IN THE NEAR FUTURE. I UNDERSTAND THAT IF I DO NOT PROVIDE A TAXPAYER IDENTIFICATION
     NUMBER WITHIN SIXTY (60) DAYS, 31% OF ALL REPORTABLE PAYMENTS MADE TO ME THEREAFTER WILL BE WITHHELD UNTIL I
     PROVIDE A NUMBER.

 

                                                                                                       
     -------------------------------------------------------------------  ------------------------------
                                  Signature                                               Date
- --------------------------------------------------------------------------------------------------------------------

 
                                        8
   8
 
                                  INSTRUCTIONS
                    PART OF THE TERMS AND CONDITIONS OF THE
                                 EXCHANGE OFFER
 
     1. DELIVERY OF THIS LETTER OF TRANSMITTAL AND OUTSTANDING NOTES.  The
tendered Outstanding Notes or a confirmation of book-entry delivery, as well as
a properly completed and executed copy or facsimile of this letter of
transmittal and any other required documents must be received by the exchange
agent at its address listed on the cover of this document before 5:00 p.m.,
central time, on the Expiration Date. YOU ARE RESPONSIBLE FOR THE DELIVERY OF
THE OUTSTANDING NOTES, THIS LETTER OF TRANSMITTAL AND ALL REQUIRED DOCUMENTS TO
THE EXCHANGE AGENT. EXCEPT UNDER THE LIMITED CIRCUMSTANCES DESCRIBED BELOW, THE
DELIVERY OF THESE DOCUMENTS WILL BE CONSIDERED TO HAVE BEEN MADE ONLY WHEN
ACTUALLY RECEIVED OR CONFIRMED BY THE EXCHANGE AGENT. WHILE THE METHOD OF
DELIVERY IS AT YOUR RISK AND CHOICE, OGLEBAY NORTON RECOMMENDS THAT YOU USE AN
OVERNIGHT OR HAND DELIVERY SERVICE RATHER THAN REGULAR MAIL. YOU SHOULD SEND
YOUR DOCUMENTS WELL BEFORE THE EXPIRATION DATE TO ENSURE RECEIPT BY THE EXCHANGE
AGENT. YOU MAY REQUEST THAT YOUR BROKER, DEALER, COMMERCIAL BANK, TRUST COMPANY
OR NOMINEE DELIVER YOUR OUTSTANDING NOTES, THIS LETTER OF TRANSMITTAL AND ALL
REQUIRED DOCUMENTS TO THE EXCHANGE AGENT. DO NOT SEND YOUR OUTSTANDING NOTES TO
OGLEBAY NORTON.
 
     If you wish to tender your Outstanding Notes, but:
 
          (a) your Outstanding Notes are not immediately available;
 
          (b) you cannot deliver your Outstanding Notes, this letter of
     transmittal and all required documents to the exchange agent before the
     Expiration Date; or
 
          (c) you are unable to complete the book-entry tender procedure before
     the Expiration Date,
 
you must tender your Outstanding Notes according to the guaranteed delivery
procedure. A summary of this procedure follows, but you should read the section
in the prospectus titled "VI.H. The Exchange Offer -- Guaranteed Delivery
Procedures" for more complete information. As used in this letter of
transmittal, an "Eligible Institution" is any participant in a Recognized
Signature Guarantee Medallion Program within the meaning of Rule 17Ad-15 of the
Exchange Act.
 
     For a tender made through the guaranteed delivery procedure to be valid,
the exchange agent must receive a properly completed and executed Notice of
Guaranteed Delivery or a facsimile of that notice before 5:00 p.m., Central
Standard time, on the Expiration Date. The Notice of Guaranteed Delivery must be
delivered by an Eligible Institution and must:
 
          (a) state your name and address;
 
          (b) list the certificate numbers and principal amounts of the
     Outstanding Notes being tendered;
 
          (c) state that tender of your Outstanding Notes is being made through
     the Notice of Guaranteed Delivery; and
 
          (d) guarantee that this letter of transmittal, or a facsimile of it,
     the certificates representing the Outstanding Notes, or a confirmation of
     DTC book-entry transfer, and all other required documents will be deposited
     with the exchange agent by the Eligible Institution within three New York
     Stock Exchange trading days after the Expiration Date.
 
     The exchange agent must receive your Outstanding Notes certificates, or a
confirmation of DTC book entry, in proper form for transfer, this letter of
transmittal and all required documents within three New York Stock Exchange
trading days after the Expiration Date or your tender will be invalid and may
not be accepted for exchange.
 
     Oglebay Norton has the sole right to decide any questions about the
validity, form, eligibility, time of receipt, acceptance or withdrawal of
tendered Outstanding Notes, and its decision will be final and binding. Oglebay
Norton's interpretation of the terms and conditions of the Exchange Offer,
including the instructions
 
                                        9
   9
 
contained in this letter of transmittal and in the prospectus under the heading
"VI.E. The Exchange Offer -- Conditions," will be final and binding on all
parties.
 
     Oglebay Norton has the absolute right to reject any or all of the tendered
Outstanding Notes if
 
          (1) the Outstanding Notes are not properly tendered or
 
          (2) in the opinion of counsel, the acceptance of those Outstanding
     Notes would be unlawful.
 
     Oglebay Norton may also decide to waive any conditions, defects, or
invalidity of tender of Outstanding Notes and accept such Outstanding Notes for
exchange. Any defect or invalidity in the tender of Outstanding Notes that is
not waived by Oglebay Norton must be cured within the period of time set by
Oglebay Norton.
 
     It is your responsibility to identify and cure any defect or invalidity in
the tender of your Outstanding Notes. Your Outstanding Notes will not be
considered to have been made until any defect is cured or waived. Neither
Oglebay Norton, the exchange agent nor any other person is required to notify
you that your tender was invalid or defective, and no one will be liable for any
failure to notify you of such a defect or invalidity in your tender of
Outstanding Notes. As soon as reasonably possible after the Expiration Date, the
exchange agent will return to the Holder tendering any Outstanding Notes that
were invalidly tendered if the defect of invalidity has not been cured or
waived.
 
     2. TENDER BY HOLDER.  You must be a Holder of Outstanding Notes in order to
participate in the Exchange Offer. If you are a beneficial holder of Outstanding
Notes who wishes to tender, but is not the registered Holder, you must arrange
with the registered Holder to execute and deliver this letter of transmittal on
his, her or its behalf. Before completing and executing this letter of
transmittal and delivering the registered Holder's Outstanding Notes, you must
either make appropriate arrangements to register ownership of the Outstanding
Notes in your name, or obtain a properly executed bond power from the registered
Holder. The transfer of registered ownership of Outstanding Notes may take a
long period of time.
 
     3. PARTIAL TENDERS.  If you are tendering less than the entire principal
amount of Outstanding Notes represented by a certificate, you should fill in the
principal amount you are tendering in the third column of the box entitled
"Description of Outstanding Notes." The entire principal amount of Outstanding
Notes listed on the certificate delivered to the exchange agent will be deemed
to have been tendered unless you fill in the appropriate box. If the entire
principal amount of all Outstanding Notes is not tendered, a certificate will be
issued for the principal amount of those untendered Outstanding Notes not
tendered.
 
     Unless a different address is provided in the appropriate box on this
letter of transmittal, certificate(s) representing Exchange Notes issued in
exchange for any tendered and accepted Outstanding Notes will be sent to the
registered Holder at his or her registered address, promptly after the
Outstanding Notes are accepted for exchange. In the case of Outstanding Notes
tendered by book-entry transfer, any untendered Outstanding Notes and any
Exchange Notes issued in exchange for tendered and accepted Outstanding Notes
will be credited to accounts at DTC.
 
     4. SIGNATURES ON THE LETTER OF TRANSMITTAL; BOND POWERS AND ENDORSEMENTS;
GUARANTEE OF SIGNATURES.
 
     - If you are the registered Holder of the Outstanding Notes tendered with
       this document, and are signing this letter of transmittal, your signature
       must match exactly with the name(s) written on the face of the
       Outstanding Notes. There can be no alteration, enlargement, or change in
       your signature in any manner. If certificates representing the Exchange
       Notes, or certificates issued to replace any Outstanding Notes you have
       not tendered are to be issued to you as the registered Holder, do not
       endorse any tendered Outstanding Notes, and do not provide a separate
       bond power.
 
     - If you are not the registered Holder, or if Exchange Note or any
       replacement Outstanding Note certificates will be issued to someone other
       than you, you must either properly endorse the Outstanding Notes you have
       tendered or deliver with this letter of transmittal a properly completed
       separate bond power. Please note that the signatures on any endorsement
       or bond power must be guaranteed by an Eligible Institution.
 
                                       10
   10
 
     - If you are signing this letter of transmittal but are not the registered
       Holder(s) of any Outstanding Notes listed on this document under the
       "Description of Outstanding Notes," the Outstanding Notes tendered must
       be endorsed or accompanied by appropriate bond powers, in each case
       signed in the name of the registered Holder(s) exactly as it appears on
       the Outstanding Notes. Please note that the signatures on any endorsement
       or bond power must be guaranteed by an Eligible Institution.
 
     - If this letter of transmittal, any Outstanding Notes tendered or any bond
       powers are signed by trustees, executors, administrators, guardians,
       attorneys-in-fact, officers of corporations, or others acting in a
       fiduciary or representative capacity, that person must indicate their
       title or capacity when signing. Unless waived by Oglebay Norton, evidence
       satisfactory to Oglebay Norton of that person's authority to act must be
       submitted with this letter of transmittal. Please note that the
       signatures on any endorsement or bond power must be guaranteed by an
       Eligible Institution.
 
     - All signatures on this letter of transmittal must be guaranteed by an
       Eligible Institution unless one of the following situations apply:
 
      - If this letter of transmittal is signed by the registered Holder(s) of
        the Outstanding Notes tendered with this letter of transmittal and such
        Holder(s) has not completed the box titled "Special Payment
        Instructions" or the box titled "Special Delivery Instructions;" or
 
      - If the Outstanding Notes are tendered for the account of an Eligible
        Institution.
 
     5. SPECIAL PAYMENT AND DELIVERY INSTRUCTIONS.  If different from the name
and address of the person signing this letter of transmittal, you should
indicate, in the applicable box or boxes, the name and address where Outstanding
Notes issued in replacement for any untendered or tendered but unaccepted
Outstanding Notes should be issued or sent. If replacement Original Notes are to
be issued in a different name, you must indicate the taxpayer identification or
social security number of the person named.
 
     6. TRANSFER TAXES.  Oglebay Norton will pay all transfer taxes, if any,
applicable to the exchange of Outstanding Notes in the Exchange Offer. However,
transfer taxes will be payable by you (or by the tendering Holder if you are
signing this letter on behalf of a tendering Holder) if:
 
     - certificates representing Exchange Notes or notes issued to replace any
       Outstanding Notes not tendered or accepted for exchange are to be
       delivered to, or are to be registered or issued in the name of, a person
       other than the registered Holder;
 
     - tendered Outstanding Notes are registered in the name of any person other
       than the person signing this letter of transmittal; or
 
     - a transfer tax is imposed for any reason other than the exchange of
       Outstanding Notes according to the Exchange Offer. If satisfactory
       evidence of the payment of those taxes or an exemption from payment is
       not submitted with this letter of transmittal, the amount of those
       transfer taxes will be billed directly to the tendering Holder. Until
       those transfer taxes are paid, Oglebay Norton will not be required to
       deliver any Exchange Notes required to be delivered to, or at the
       direction of, such tendering Holder.
 
     Except as provided in this Instruction 6, it is not necessary for transfer
tax stamps to be attached to the Outstanding Notes listed in this letter of
transmittal.
 
     7. FORM W-9.  You must provide the exchange agent with a correct Taxpayer
Identification Number ("TIN") for the Holder on the enclosed Form W-9. If the
Holder is an individual, the TIN is his or her social security number. If you do
not provide the required information on the Form W-9, you may be subject to 31%
Federal income tax withholding on certain payments made to the Holders of
Exchange Notes. Certain Holders, such as corporations and certain foreign
individuals, are not subject to these backup withholding and reporting
requirements. For additional information, please read the enclosed Guidelines
for Certification of TIN on Substitute Form W-9. To prove to the exchange agent
that a foreign individual qualifies as an exempt Holder, the foreign individual
must submit a Form W-8, signed under penalties of perjury, certifying as to that
individual's exempt status. You can obtain a Form W-8 from the exchange agent.
 
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     8. WAIVER OF CONDITIONS.  Oglebay Norton may choose, at any time and for
any reason, to amend, waive or modify certain of the conditions to the Exchange
Offer. The conditions applicable to tenders of Outstanding Notes in the Exchange
Offer are described in the prospectus under the heading "VI.E. The Exchange
Offer -- Conditions."
 
     9. MUTILATED, LOST, STOLEN OR DESTROYED OUTSTANDING NOTES.  If your
Outstanding Notes have been mutilated, lost, stolen or destroyed, you should
contact the exchange agent at the address listed on the cover page of this
document for further instructions.
 
     10. REQUESTS FOR ASSISTANCE OR ADDITIONAL COPIES.  If you have questions,
need assistance, or would like to receive additional copies of the prospectus or
this letter of transmittal, you should contact the exchange agent at the address
listed in the prospectus. You may also contact your broker, dealer, commercial
bank, trust company, or other nominee for assistance concerning the Exchange
Offer.
 
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            GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
                         NUMBER ON SUBSTITUTE FORM W-9
 
GUIDELINES FOR DETERMINING THE PROPER IDENTIFICATION NUMBER TO GUIDE THE
PAYER.-- Social Security Numbers have nine digits separated by two hyphens: i.e.
000-00-0000. Employer Identification Numbers have nine digits separated by only
one hyphen: i.e. 00-0000000. The table below will help determine the number to
give the payer.
 


                               
- ----------------------------------------------------------
                                          GIVE THE
                                       SOCIAL SECURITY
    FOR THIS TYPE OF ACCOUNT:            NUMBER OF--
- ----------------------------------------------------------
                             
 1.  An individual's account.      The individual
 2.  Two or more individuals       The actual owner of the
     (joint account)               account or, if combined
                                   funds, the first
                                   individual on the
                                   account(1)
 3.  Custodian account of a minor  The minor(2)
     (Uniform Gift to Minors Act)
 4.  a. The usual revocable        The grantor-trustee(1)
       savings trust account
       (grantor is also trustee)
     b. So-called trust account    The actual owner(1)
       that is not a legal or
       valid trust under State
       law
 5.  Sole proprietorship account   The owner(3)
 
- ----------------------------------------------------------

 


                             
- ----------------------------------------------------------
                                      GIVE THE EMPLOYER
                                       IDENTIFICATION
    FOR THIS TYPE OF ACCOUNT:            NUMBER OF--
- ----------------------------------------------------------
                             
 6.  A valid trust, estate, or     The legal entity (Do
     pension trust                 not furnish the
                                   identifying number of
                                   the personal
                                   representative or
                                   trustee unless the
                                   legal entity itself is
                                   not designated in the
                                   account title.)(4)
 7.  Corporate account             The corporation
 8.  Religious, charitable, or     The organization
     educational organization
     account
 9.  Partnership                   The partnership
10.  Association, club or other    The organization
     tax-exempt organization
11.  A broker or registered        The broker or nominee
     nominee
12.  Account with the Department   The public entity
     of Agriculture in the name
     of a public entity (such as
     a State or local government,
     school district, or prison)
     that receives agricultural
     program payments
- ----------------------------------------------------------

 
(1) List first and circle the name of the person whose number you furnish. If
    only one person on a joint account has a Social Security Number, that
    person's number must be furnished.
(2) Circle the minor's name and furnish the minor's Social Security Number.
(3) Show the name of the owner. You may also enter your business name. You may
    use your Social Security Number or Employer Identification Number.
(4) List first and circle the name of the legal trust, estate, or pension trust.
 
     NOTE: If no name is circled when there is more than one name, the number
           will be considered to be that of the first name listed.
 
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            GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
                         NUMBER ON SUBSTITUTE FORM W-9
 
OBTAINING A NUMBER
If you don't have a Taxpayer Identification Number or you don't know your
number, obtain Form SS-5, Application for a Social Security Number Card, or Form
SS-4, Application for Employer Identification Number, at the local office of the
Social Security Administration or the Internal Revenue Service and apply for a
number.
 
PAYEES EXEMPT FROM BACKUP WITHHOLDING
Payees specifically exempted from backup withholding on broker transactions
include the following:
  - A corporation.
  - A financial institution.
  - An organization exempt from tax under Section 501(a), an individual
    retirement plan, or a custodial account under Section 403(b)(7), if the
    account satisfies the requirements of Section 401(f)(2).
  - The United States or any agency or instrumentality thereof.
  - A State, the District of Columbia, a possession of the United States, or any
    subdivision or instrumentality thereof.
  - A foreign government, a political subdivision of a foreign government, or
    any agency or instrumentality thereof.
  - An international organization or any agency or instrumentality thereof.
  - A dealer in securities or commodities required to be registered in the
    United States, the District of Columbia, or a possession of the United
    States.
  - A real estate investment trust.
  - A futures commissions merchant registered with the Commodity Futures Trading
    Commission.
  - A common trust fund operated by a bank under Section 584(a).
  - An entity registered at all times under the Investment Company Act of 1940.
  - A foreign central bank of issue.
  - A person registered under the Investment Advisors Act of 1940 who regularly
    acts as a broker.
  Payments of dividends not generally subject to backup withholding include the
    following:
  - Payments to nonresident aliens subject to withholding under Section 1441.
  - Payments to partnerships not engaged in a trade or business in the United
    States and which have at least one nonresident partner.
  - Payments of patronage dividends where the amount received is not paid in
    money.
  - Payments made by certain foreign organizations.
  - Payments described in Section 404(k) made by an employee stock ownership
    plan.
  Payments of interest not generally subject to backup withholding include the
    following:
  - Payments of interest on obligations issued by individuals. Note: You may be
    subject to backup withholding if this interest is $600 or more and is paid
    in the course of the payer's trade or business and you have not provided
    your correct Taxpayer Identification Number to the payer.
  - Payments of tax-exempt interest (including tax-exempt interest dividends
    under Section 852).
  - Payments described in Section 6049(b)(5) to nonresident aliens.
  - Payments on tax-free covenant bonds under Section 1451.
  - Payments made by certain foreign organizations.
  - Payments of mortgage interest to you.
  Exempt payees described above should file Substitute Form W-9 to avoid
  possible erroneous backup withholding. FILE THIS FORM WITH THE PAYER, FURNISH
  YOUR TAXPAYER IDENTIFICATION NUMBER, WRITE "EXEMPT" ON THE FACE OF THE FORM,
  SIGN AND DATE THE FORM AND RETURN IT TO THE PAYER.
 
    PRIVACY ACT NOTICE -- Section 6109 requires most recipients of dividend,
  interest, or other payments to give Taxpayer Identification Numbers to payers
  who must report the payments to the IRS. The IRS uses the numbers for
  identification purposes. Payers must be given the numbers whether or not
  recipients are required to file tax returns. Payers must generally withhold
  31% of taxable interest, dividend, and certain other payments to a payee who
  does not furnish a Taxpayer Identification Number to a payer. Certain
  penalties may also apply.
 
PENALTIES
(1) PENALTY FOR FAILURE TO FURNISH TAXPAYER IDENTIFICATION NUMBER. -- If you
fail to furnish your Taxpayer Identification Number to a payer, you are subject
to a penalty of $50 for each such failure unless your failure is due to
reasonable cause and not to willful neglect.
(2) CIVIL PENALTY FOR FALSE INFORMATION WITH RESPECT TO WITHHOLDING. -- If you
make a false statement with no reasonable basis which results in no imposition
of backup withholding, you are subject to a penalty of $500.
(3) CRIMINAL PENALTY FOR FALSIFYING INFORMATION. -- Falsifying certifications or
affirmations may subject you to criminal penalties including fines and/or
imprisonment.
 
                  FOR ADDITIONAL INFORMATION CONTACT YOUR TAX
                             CONSULTANT OR THE IRS.
 
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                         (DO NOT WRITE IN SPACE BELOW)
 

                                                                
           CERTIFICATE                     OUTSTANDING NOTES                  OUTSTANDING NOTES
           SURRENDERED                         TENDERED                           ACCEPTED
 
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Delivery Prepared by:
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Checked by:
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Date: 
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