EXHIBIT 2.1.1

                     AMENDMENT NO. 1 TO PURCHASE AGREEMENT

     THIS AMENDMENT NO. 1 TO THE PURCHASE AGREEMENT is made as of this 1st day
of October, 1999, among U.S. Silica Company, a Delaware Corporation; Joseph H.
Shearer; R. Scott Shearer; CATS, Inc., a Pennsylvania corporation; the JHS
Family Partnership, a Pennsylvania limited partnership; the RSS Family
Partnership, a Pennsylvania limited partnership; and the Dell H. Shearer
Grandchildren's Trust, a Pennsylvania Trust.

     WHEREAS, the parties previously entered into a Purchase Agreement dated as
of August 26, 1999 ("Purchase Agreement") and now desire to amend the Purchase
Agreement in certain respects as set forth herein;

     NOW THEREFORE, in consideration of this premise and intending to be legally
bound hereby, the parties hereto agree as follows:

     1.   The term "Sellers" shall be deleted and replaced with the term
          "Shareholders" in Section 2.5(b) of the Purchase Agreement.

     2.   The following two new paragraphs shall be added to Section 2.5(b) of
          the Purchase Agreement:

          Buyer agrees that if and when Commercial or Buyer receives all or any
          portion of the S Corp Tax Deposit, Buyer shall or shall cause
          Commercial to pay to the Shareholders the full amount so received
          within three business days after receipt thereof. If (i) Commercial or
          Buyer receives notification that the IRS has offset the full amount of
          the S Corp Tax Deposit, or (ii) the amount so received by Commercial
          or the Buyer and paid to the Shareholders is not equal to the full
          amount of the S Corp Tax Deposit, because such full amount has been
          offset by the IRS, and, in either case, such offset is in respect of
          Tax Liabilities of Commercial or the Buyer related to any period
          beginning on or after the Closing Date (a "Buyer Caused Offset"), then
          the Buyer shall also pay to the Shareholders the amount of such Buyer
          Caused Offset. If, however, any such offset is in respect of Tax
          liabilities of Commercial or the Shareholders related to any period
          occurring prior to the Closing Date, then the Buyer shall only be
          responsible for paying to the Shareholders such amount that has been
          actually received by Commercial or Buyer (plus the amount of any Buyer
          Caused Offset, if any).

          Upon payment by the Buyer or Commercial to the Shareholders of the
          amounts required by this Section 2.5(b), the Buyer and the
          Shareholders shall (i) execute and deliver to Lion Abstract Limited
          Partnership a joint written instruction stating that the Escrow
          Agreement for the S Corp Tax Deposit is terminated, effective
          immediately and (ii) execute and deliver a joint written instruction
          to Banque Nationale De Paris, New York Branch instructing Banque
          Nationale De Paris, New York Branch to immediately cancel the letter
          of credit for the S Corp Tax Deposit, provided the letter of credit in
          respect of the S Corp Tax Deposit has not terminated in accordance
          with its terms.


     3.   The parties agree that the information and documents referenced in
          clauses (a) and (b) of the first sentence of Section 12.5 of the
          Purchase Agreement shall include, without limitation, all that
          necessary or desirable in determining the boundaries of the Property.

     4.   The Sellers agree that $4,000,000 of the Aggregate Purchase Price owed
          to Joseph H. Shearer as a Seller of the Acquired Shares and $4,000,000
          of the Aggregate Purchase Price owed to R. Scott Shearer a Seller of
          the Acquired Shares shall be used to fund the Closing Escrow Amount.

     5.   This Amendment may be executed in one or more counterparts, all of
          which together shall be deemed to be one and the same instrument
          binding upon the parties hereto.

     6.   This Amendment shall be governed by and construed and interpreted in
          accordance with the laws of the Commonwealth of Pennsylvania.

     7.   This Amendment shall be binding upon the parties hereto and their
          respective heirs, personal representatives, successors and assigns.

     8.   Except as specifically amended by this Amendment, the Purchase
          Agreement and the provisions thereof shall continue in full force and
          effect without modification.

     9.   Capitalized terms not defined herein shall have the meaning assigned
          to them in the Purchase Agreement.


     IN WITNESS WHEREOF, the parties have executed and delivered this Agreement
as of the date first written above.

Buyer:

US SILICA COMPANY                                Sellers:

By: /s/                                          SHAREHOLDERS:
   ------------------

                                                 /s/ Joseph H. Shearer
                                                 ---------------------------

                                                 Joseph H. Shearer

                                                 /s/ R. Scott Shearer
                                                 ---------------------------

                                                 R. Scott Shearer

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                                         COMMERCIAL AGGREGATES TRANSPORTATION
                                         AND SALES, L.P.

                                         By:  CATS, Inc., General Partner

                                         By: /s/
                                            ---------------------------------

                                         Title:  Pres.
                                               ------------------------------

                                         By:  JHS Family Partnership

                                         By: /s/
                                            ---------------------------------

                                         General Partner

                                         By:  RSS Family Partnership

                                         By: /s/
                                            ---------------------------------

                                         General Partner

                                         By: The Dell H. Shearer Grandchildren's
                                         Trust

                                         By: /s/
                                            ---------------------------------

                                         Co-Trustee

                                         By: /s/
                                            ---------------------------------

                                         Co-Trustee

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