1. Adwan Chemical Industries Co. Ltd.
2. AGSCO Corporation
3. Akbaba Agriculture Inc.
4. Australian Silica Quartz Group Limited
5. Badger Mining Corporation
6. CDE Group
7. Chongqing Changjiang River Moulding Material Group Co. Ltd.
8. Covia Holdings LLC
9. Deejay Enterprises
10. EUROQUARZ GmbH
11. Gujarat Mineral Development Corporation Ltd.
12. Hisagoya Co. Ltd.
13. IC & C Minerals
14. JFE Steel Corporation
15. Merck KGaA
16. Mitsubishi Corporation
17. Nikunj Enterprises
18. SCR-Sibelco NV
19. Short Mountain Silica Co. by Thiele Kaolin Company
20. superior silica sands
21. Terex Corporation
22. Tochu Corporation
23. U.S. Silica Holdings Inc.
24. Ultra High Purity Quartz
25. VRX Silica Limited