1. Black Hills Bentonite LLC
2. Charles B. Chrystal Co. Inc.
3. Cimbar Performance Minerals Inc.
4. Clariant AG
5. Delta Corp Sdn Bhd.
6. Halliburton Energy Services Inc.
7. Kemira Oyj
8. Maxworth International Pty. Ltd.
9. MIDPOINT Chemicals Company
10. Minerals Technologies Inc.
11. Schlumberger Limited
12. Thermo Fisher Scientific Inc.
13. Volclay Japan Co. Ltd.
14. Wyo-Ben Inc.