Contract

EXHIBIT 10.6        

            A Severance Agreement has been executed by the Company and the indicated employee, substantially identical in all material respects to the form of Severance Agreement filed as Exhibit 10.6 to the Company's 2000 Annual Report on Form 10-K except as noted below.

EMPLOYEE	POSITION	DATE OF AGREEMENT
Xxxxxx X. Xxxxxxx	Vice President, Organization     and Human Resources	March 15, 2002
Xxxxx Xxxxxxx-Aubertot	Senior Vice President,       Managing Director, Minteq	November 25, 2002
Xxxxxxx X. Xxxxxxx	Vice President - Controller      and Chief Accounting Officer	March 1, 2001
Xxxx X. Xxxxxxx	Vice President, General Counsel and Secretary	December 1, 2004

D. Xxxxx Xxxxxxxx	Vice President and Managing        Director, Performance Minerals	March 15, 2002
Xxxxxxx Xxxxxxxx	Vice President - Xxxxx	Xxxxx 0, 0000
Xxxxxxx Xxxxxxxxx	Senior Vice President,  and Managing  Director Paper PCC	March 1, 2001
Xxxx X. Xxxxxxxxxx	Chairman, President and         Chief Executive Officer	January 1, 1997
Xxxx X. Xxxxx	Senior Vice President -       Chief Financial Officer	March 1, 2001