| 1 | Hydrophobic silica is the active antifoam agent. | |
| 2 | "There's no difference in principle between neurons and silicon, " he said. | |
| 3 | Beneficiation removes clay and silica to considerable extent. | |
| 4 | The commercial product however, containing silica and silicates, has a positive effect . | |
| 5 | Moissanite has not been found in large enough quantities naturally to be used for jewelry. |