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                                                                    EXHIBIT 99.4

                       UNITED STATES LIME & MINERALS, INC.
                         13800 Montfort Drive, Suite 330
                               Dallas, Texas 75240

                               [November   ], 2000

Dear Shareholder:

         Enclosed are the prospectus and other materials relating to the Rights
Offering by United States Lime & Minerals, Inc. Please carefully review the
prospectus, which describes how you can participate in the Rights Offering. You
will be able to exercise your Subscription Rights to purchase additional shares
of United States Lime & Minerals Common Stock only during a limited period. You
will find answers to some frequently asked questions about the Rights Offering
beginning on page 1 of the prospectus. You should also refer to the detailed
Instructions for Use of United States Lime & Minerals, Inc. Subscription
Certificates, included with this letter. The exercise of Subscription Rights
will be irrevocable.

SUMMARY OF THE TERMS OF THE OFFERING.

     -   You will receive [  ] non-transferable Subscription Rights for each
         share of United States Lime & Minerals Common Stock you owned on
         [November   ], 2000. You will not receive fractional Subscription
         Rights, but United States Lime & Minerals will round your number of
         Subscription Rights down to the nearest whole number. For example, if
         you own [100] shares of Common Stock, you will receive [    ]
         Subscription Rights. If you own [50] shares of Common Stock, you will
         receive [    ] Subscription Rights.

     -   You may purchase one share of Common Stock for each Subscription Right
         you receive at the Subscription Price of $[    ] per share.

     -   If you fully exercise the Subscription Rights issued to you, you may
         subscribe for additional shares through the Over-Subscription
         Privilege. If Subscription Rights holders subscribe to purchase more
         than a total of [        ] shares, shares purchased through the
         Over-Subscription Privilege will be allocated, based upon the number of
         shares each over-subscribing shareholder subscribed for pursuant to the
         Basic Subscription Privilege, as more fully described in the
         prospectus.

     -   The Rights Offering expires at 5:00 p.m., Eastern Standard Time, on [
         ], 2000. If you do not exercise your Subscription Rights before that
         time, they will expire and will not be exercisable for shares of Common
         Stock.

         If your shares are held in your name, a Subscription Certificate is
enclosed. If you are a current or former employee who holds shares in the
Company's 401(k) plan (formerly the


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ESOP), the subscription rights attributable to those shares are included in your
Subscription Certificate. If your shares are otherwise held in the name of your
bank or broker, you must contact your bank or broker if you wish to participate
in this offering.

         If you do not exercise your Subscription Rights, your ownership in
United States Lime & Minerals may be diluted. Please see page 6 of the
prospectus for a discussion of dilution and other risk factors.

         If you have any questions concerning the Rights Offering, please feel
free to contact United States Lime & Minerals, Inc.'s Vice President of Finance,
Company Secretary and Corporate Controller, Larry T. Ohms, at (972) 991-8400.

                                      Sincerely,



                                      Herbert G.A. Wilson
                                      President and CEO


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