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                                                                   Exhibit 10(s)

                               SIXTH AMENDMENT TO
                AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT

         This Sixth Amendment to Amended and Restated Loan and Security
Agreement (this "Sixth Amendment") dated as of January 31, 2003 by and among
United States Lime & Minerals, Inc., a Texas corporation ("U.S. Lime"), Texas
Lime Company, a Texas corporation ("TLC"), and Arkansas Lime Company, an
Arkansas corporation ("ALC," and together with U.S. Lime and TLC, collectively
referred to as the "Borrowers" and individually as a "Borrower"), and Wachovia
Bank, National Association, formerly known as First Union National Bank, as
successor to CoreStates Bank, N.A. ("Bank").

                                   BACKGROUND

         A. Borrowers and Bank are parties to an Amended and Restated Loan and
Security Agreement dated December 30, 1997, as amended by (i) the First
Amendment to Amended and Restated Loan and Security Agreement, (ii) the Second
Amendment to Amended and Restated Loan and Security Agreement, (iii) a letter
agreement dated as of April 21, 2000, (iv) the Third Amendment to Amended and
Restated Loan and Security Agreement dated as of April 26, 2001, (v) the Fourth
Amendment to Amended and Restated Loan and Security Agreement dated as of
December 31, 2001, and (vi) the Fifth Amendment to Amended and Restated Loan and
Security Agreement dated as of May 31, 2002 (as the same has been amended and
may hereafter be amended, restated, supplemented or otherwise modified and in
effect from time to time, the "Loan Agreement"), pursuant to which Bank
continued and restated certain credit facilities for the benefit of Borrowers
under the terms and conditions set forth therein. All initially capitalized
terms used in this Sixth Amendment, unless otherwise specifically defined
herein, shall have the meanings ascribed to them in the Loan Agreement.

         B. Bank and Borrowers desire to further amend the Loan Agreement to
extend the maturity date of the Revolving Credit according to the terms hereof.

         NOW, THEREFORE, in consideration of the foregoing and of the mutual
covenants set forth herein, the parties hereto, intending to be legally bound
hereby, agree as follows:

                  1. Ratification. This Sixth Amendment is a modification of the
Loan Agreement pursuant to Section 9.2 thereof. Except as expressly set forth
herein, or in any amendment to any of the documents referred to herein,
Borrowers and Bank acknowledge and agree that each and every term, condition and
provision of the Loan Agreement is hereby ratified and confirmed in full.

                  2. Revolving Credit Termination Date Extended. The defined
term "Revolving Credit Termination Date" is hereby amended and restated in its
entirety as of the date hereof as follows:

                  "Revolving Credit Termination Date" means July 31, 2003, or
                  such later date as Borrowers and Bank may agree in writing.

                  3. Outstanding Indebtedness. Borrowers hereby unconditionally
acknowledge that, as of the date hereof, the outstanding principal balance under
the Revolving Credit is $2,000,000, and the aggregate face amount of outstanding
undrawn Letters of Credit is $133,000. Borrowers acknowledge and agree that the
foregoing balance of the Revolving Credit (including the amount of all draws
under outstanding Letters of Credit), together with interest, which shall accrue
from the date hereof at the rates set forth in the Loan Agreement, is owing to
Bank without claim, counterclaim, recoupment, defense or setoff of any kind.

                  4. Extension Fee. Borrowers agree to pay Bank a fee in the
amount of $6,250 on February 28, 2003 if on that date (i) the outstanding
principal balance of, and all accrued and unpaid interest on, the Revolving
Credit has not been repaid in full, and (ii) the commitment to make advances
thereunder has not been terminated.

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         5. Representations and Warranties. To induce Bank to enter into this
Sixth Amendment, Borrowers jointly and severally represent and warrant to Bank
as follows:

                  5.1 After giving effect to the modifications contained herein,
all representations, warranties and covenants made by Borrowers to Bank in the
Loan Agreement (except those relating to a specific date) are true and correct
in all material respects as of the date hereof, with the same force and effect
as though made as of the date hereof;

                  5.2 No Event of Default or Unmatured Event of Default has
occurred and is continuing under the Loan Agreement as of the date hereof;

                  5.3 Each Borrower is a corporation validly subsisting under
the laws of the state of its incorporation; the execution, delivery and
performance of this Sixth Amendment and any other documents and instruments
executed and delivered to Bank in connection herewith (i) are within each
Borrower's corporate powers, (ii) have been duly authorized by each Borrower's
Board of Directors, (iii) do not contravene any provision of law or any
indenture, agreement or undertaking to which any Borrower is a party or is
otherwise bound, any Borrower's Certificate of Incorporation or bylaws, or any
resolution of the Board of Directors of any Borrower, and (iv) require no
consent or approval of any governmental authority or any third party; and

                  5.4 This Sixth Amendment and any other documents and
instruments executed by a Borrower and delivered to Bank in connection herewith
have been validly executed and are enforceable against the Borrower or Borrowers
party thereto in accordance with their respective terms.

Any failure of any of the representations and warranties made by Borrowers in
this Sixth Amendment to be true and correct in all material respects when made
shall constitute an Event of Default under the Loan Agreement.

         6. Conditions Precedent. The effectiveness of this Sixth Amendment, and
the performance by Bank of its obligations described herein, are subject to the
conditions precedent that Bank shall have received, in form and substance
satisfactory to Bank:

                  6.1 resolutions of the Boards of Directors of each Borrower
authorizing the execution, delivery and performance of this Sixth Amendment and
the other documents and instruments executed and delivered to Bank in connection
herewith, certified by such Borrower's Secretary that the same are true and
complete copies of the originals thereof and remain in full force and effect,
not having been modified or rescinded; and

                  6.2 a completed and executed Borrowing Base Certificate for
the month ended December 31, 2002.

         7. Miscellaneous.

                  7.1 Entire Agreement. The Loan Agreement, as amended by this
Sixth Amendment, and the other Loan Documents, embody the entire agreement and
understanding between Bank and Borrowers. The Loan Agreement, together with this
Sixth Amendment, and all documents executed and delivered in connection
herewith, supersede all prior agreements and understandings relating to subject
matter hereof. This Sixth Amendment together with the Loan Agreement, and the
documents executed and delivered in connection herewith and therewith shall be
construed as one agreement, and in the event of any inconsistency, the
provisions of any promissory note evidencing a portion of the Indebtedness shall
control over the provisions of this Sixth Amendment.

                  7.2 Counterparts. This Sixth Amendment may be executed in any
number of counterparts and by different parties on separate counterparts, each
of which counterparts, when so


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executed and delivered, shall be deemed to be an original and all of which
counterparts, taken together, shall constitute but one and the same agreement.
This Sixth Amendment shall be effective upon the execution and delivery of a
counterpart hereof by each of the parties hereto.

                  7.3 Captions. The captions or headings in this Sixth Amendment
are for convenience of reference only and in no way define, limit, or describe
the scope or intent of any provision of this Sixth Amendment.

                  7.4 Successors and Assigns; Governing Law. This Sixth
Amendment shall be binding upon and inure to the benefit of the respective
parties hereto and their successors and assigns and shall be governed by, and
construed and enforced in accordance with, the internal laws of the Commonwealth
of Pennsylvania without regard to its principles of conflicts of laws.

         IN WITNESS WHEREOF, the undersigned have executed this Sixth Amendment
as of the day and year first written above.


                                   BANK:

                                      WACHOVIA BANK, NATIONAL ASSOCIATION,
                                      f/k/a First Union National Bank
                                      (successor to CoreStates Bank, N.A.)


                                      By:
                                         ------------------------------------
                                             Alex A. Diffey, Jr.,
                                             Senior Vice President



                                   BORROWERS:

                                      UNITED STATES LIME & MINERALS, INC.
Attest:

By:                                   By:
   --------------------------            ------------------------------------
                                             M. Michael Owens, Vice President
                                             and Chief Financial Officer

                                      TEXAS LIME COMPANY


By:                                   By:
   --------------------------            ------------------------------------
                                             M. Michael Owens, Vice President


                                      ARKANSAS LIME COMPANY


By:                                   By:
   --------------------------            ------------------------------------
                                             M. Michael Owens, Vice President


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