| Silicon Oxide | Aluminum Oxide | Magnesium Oxide |
| Titanium Oxide | Zirconium Oxide |
| ATI Wah Chang | H.C. Starck | Imerys (Kentucky-Tennessee Clay Co.) |
| Malvern Minerals Company | Michelman® | Minelco Inc. |
| Mo-Sci Corporation | NanoScale | NAPCO |
| Sapco | Sphere One Inc | Thermal Ceramics |