FIRST SUPPLEMENTAL INDENTURE

Exhibit 4.2

FIRST SUPPLEMENTAL INDENTURE, dated as of January 20, 2005 (this “First Supplemental Indenture”), between Albemarle Corporation, a Virginia corporation (the “Company”), whose principal office is located at 330 South Fourth Street, Richmond, Virginia 23219 and The Bank of New York, a New York banking corporation, as trustee (the “Trustee”).

W I T N E S S E T H

WHEREAS, the Company and the Trustee have duly executed and delivered an Indenture, dated as of January 20, 2005 (the “Indenture”), providing for the authentication, issuance, delivery and administration of unsecured notes, debentures or other evidences of indebtedness to be issued in one or more series by the Company (herein called a “Security” or the “Securities”);

WHEREAS, pursuant to the terms of the Indenture, the Company desires to provide for the establishment of a series of Securities (the “Notes”) to be issued under the Indenture in an initial aggregate principal amount of $325,000,000, which may be authenticated and delivered as provided in the Indenture;

WHEREAS, the Company desires to amend and supplement the provisions of the Indenture to issue the Notes under the terms of the Indenture as supplemented hereby;

WHEREAS, Section 9.01 of the Indenture expressly permits the Company and the Trustee to enter into one or more supplemental indentures for the purposes, inter alia , of establishing the forms and terms of Securities to be issued under the Indenture, and permits the execution of such supplemental indentures without the consent of the Holders of any Securities then outstanding;

WHEREAS, for the purposes hereinabove recited, and pursuant to due corporate action, the Company has duly determined to execute and deliver to the Trustee this First Supplemental Indenture; and

WHEREAS, all conditions and requirements necessary to make this First Supplemental Indenture a valid instrument in accordance with its terms have been done and performed, and the execution and delivery hereof have been in all respects duly authorized;

NOW, THEREFORE, in consideration of the premises, the Company and the Trustee mutually covenant and agree as follows:

SECTION 1. DEFINITIONS.

1.1 All terms contained in this First Supplemental Indenture shall, except as specifically provided herein or except as the context may otherwise require, have the meanings given to such terms in the Indenture.

1.2 Unless the context otherwise requires, the following terms shall have the following meanings:

“Depositary” means The Depository Trust Company or any other depositary from time to time specified with respect to the Notes pursuant to the Indenture.

“Global Note Legend” means the legend for the Global Securities substantially in the form set forth in Section 2.04 of the Indenture.

“Global Notes” mean Notes constituting Global Securities substantially in the form of Exhibit A hereto.

“Notes” shall have the meaning given such term in the second “Whereas” clause of this First Supplemental Indenture.

SECTION 2. TERMS AND CONDITIONS OF THE SECURITIES.

There is hereby authorized the following series of Notes:

2.1 5.10% Senior Notes due 2015 .

(a) A new series of senior unsecured Notes is hereby authorized and designated as the “5.10% Senior Notes due 2015”.

(b) The 5.10% Senior Notes due 2015 shall be issued in an initial aggregate principal amount $325,000,000, subject to adjustment as described in the form of Note attached hereto as Exhibit A. The Notes shall bear interest at a rate of 5.10% per annum, shall mature on February 1, 2015 and shall be subject to optional redemption at any time by the Company pursuant to the terms set forth in the form of Note attached hereto as Exhibit A.

(c) The Company shall be permitted to amend this First Supplemental Indenture in order to increase the aggregate principal amount of Notes that may be issued hereunder without the consent of the Holders of the Notes or the Securities of any series so affected. Any such additional Notes will have the same terms as the Notes and will rank equal to the Notes in all respects (or in all respects except for the payment of interest accruing prior to the issue date of the additional Notes or except in certain circumstances for the first payment of interest following the issue) so that the additional Notes may be consolidated and form a single series of Securities with the Notes and have the same terms as to status, redemption and otherwise as the Notes that are the subject of this First Supplemental Indenture.

2.2 Form of Global Notes . The Notes shall initially be issued in the form of Global Notes (including the Global Note Legend thereon and the “Schedule of Increases and Decreases in the Global Note” attached thereto). Each Global Note shall represent such of the outstanding Notes as shall be specified therein and each shall provide that it shall represent the aggregate principal amount of outstanding Notes from time to time endorsed thereon and that the aggregate principal amount of outstanding Notes represented thereby may from time to time be reduced to reflect any redemptions and be increased to reflect the issuance of any additional Notes. Any endorsement of a Global Note to reflect the amount of any decrease or increase in

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the aggregate principal amount of outstanding Notes represented thereby shall be made by the Trustee, as custodian of the Global Notes.

2.3 Paying Agent and Security Registrar . The Company hereby appoints the Trustee as initial Paying Agent and Security Registrar for the Notes and the Trustee hereby accepts such appointments.

2.4 Security Register and Office or Agency Pursuant to Section 10.02 of the Indenture. Pursuant to Section 3.05 of the Indenture, the Company shall maintain the Security Register in the City of New York, Borough of Manhattan, at the office designated from time to time by the Trustee, which will initially be the office of the Trustee located at 101 Barclay Street, Floor 7E, New York, New York 10286, and which shall also be the office or agency designated in accordance with Section 10.02 of the Indenture.

2.5 Procedures Regarding Optional Redemption. Under and pursuant to the Notes, the Company has been granted the option to redeem the Notes, in whole or in part, at ay time at a redemption price specified in the form of Note attached hereto as Exhibit A. If the Company exercises its option to redeem the Notes, it hereby agrees to (i) upon request by the Trustee, promptly consult with the Trustee regarding the employment of an Independent Investment Banker (as defined in the Notes), (ii) provide to the Trustee the Company Order and notice specified by Section 11.02 of the Indenture, (iii) obtain from each of the required Reference Treasury Dealers (as defined in the Notes) the Referenced Treasury Dealer Quotations (as defined in the Notes) and furnish such to the Trustee, and (iv) upon receiving from the Trustee the Comparable Treasury Price (as defined in the Notes), to provide to the Trustee on or before the first Business Day preceding such redemption date the calculation of the Redemption Price to be paid on the Notes being redeemed. In that regard, the Trustee agrees to furnish to the Company on or before the second Business Day preceding the redemption date the Comparable Treasury Price.

SECTION 3. MISCELLANEOUS.

3.1 Ratification of Indenture . The Indenture, as supplemented by this First Supplemental Indenture, is in all respects ratified and confirmed, and this First Supplemental Indenture shall be deemed a part of the Indenture in the manner and to the extent herein and therein provided.

3.2 GOVERNING LAW . This First Supplemental Indenture and each Note shall be governed by, and construed in accordance with, the laws of the State of New York.

3.3 Counterparts . This First Supplemental Indenture may be executed in several counterparts, each of which shall be an original, and all collectively but one and the same instrument.

3.4 The Trustee . The Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this First Supplemental Indenture or for or in respect of the recitals contained herein, all of which are made solely by the Company. All rights, privileges, protections, indemnities and benefits granted or afforded to the Trustee under the Indenture shall be deemed incorporated herein by this reference and shall be applicable to all actions taken, suffered or omitted by the Trustee under this First Supplemental Indenture.

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IN WITNESS WHEREOF, the parties hereto have caused this First Supplemental Indenture to be executed as of the date first above written.

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EXHIBIT A

[FACE OF NOTE]

[insert if the Note is a Global Note: THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS SECURITY MAY NOT BE EXCHANGED OR TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY, EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE.

UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITARY TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY SECURITY ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITARY (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITARY), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.]

ALBEMARLE CORPORATION

            5.10% Senior Notes due 2015

Albemarle Corporation, a corporation duly organized and existing under the laws of the Commonwealth of Virginia (herein called the “Company,” which term includes any successor Person under the Indenture hereinafter referred to), for value received, hereby promises to pay to                      , or registered assigns, the principal sum of                     

A-1

Dollars [, if the Note is a Global Note, insert —, as revised by the Schedule of Increases and Decreases in the Global Note attached hereto,] on February 1, 2015 and to pay interest thereon from                      , 2005 or from the most recent Interest Payment Date to which interest has been paid or duly provided for, semi-annually on February 1 and August 1 in each year, commencing August 1, 2005, at the rate of 5.10% per annum, until the principal hereof is paid or made available for payment, provided that any principal and premium, and any such installment of interest, which is overdue shall bear interest at the rate of 5.10% per annum (to the extent that the payment of such interest shall be legally enforceable), from the dates such amounts are due until they are paid or made available for payment, and such interest shall be payable on demand. Interest will be computed on the basis of a 360-day year of twelve 30-day months. The interest so payable, and punctually paid or duly provided for (except for Defaulted Interest), on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Note (or one or more Predecessor Securities) is registered at the close of business on the Regular Record Da