Crystals
TopGeneral Information
Silicon carbide is also known as carborundum. It can rarely be found in nature as moissanite, almost all of the silicon carbide on this planet is synthetic. It can be produced with many different types of crystal structures, usually it's polymorf (alpha silicon carbide).[1]
TopProduction Methods
Silicon carbide can be produced by combining silicon and carbon at high temperatures in an Acheson graphite electric resistance furnace. This a process type called pyrolysis. It can also be produced with the Lely process, which is a vapor deposition technique using silicon carbide powder to get very pure crystals.[1]
TopChemical & Physical Information
| Trivial Name | Carborundum |
| Chemical Name | Silicon Carbide |
| Other names | Carborundum (EN,NL,BE) |
| Type of chemical | Covalent compound |
| Chemical Formula | SiC |
| CAS number | 409-21-2 |
| Crystal system | Hexagonal (most common) |
| Bravais lattice | Rhombohedral |
| Coordination geometry | Octahedral |
| Hardness (Mohs) | 9.5 |
| Young's modulus | 400-700 GPa |
| Colour | Black, blue, green |
| Luster | Metallic |
| Streak | Greenish gray |
| Opacity | Opaque to translucent and transparent. |
| Safety summary | Safe |
| Safety data | MSDS |
| Production method | Pyrolysis, vapor deposition. |
| Storage | Nothing special. |
| Extra | Used for drills and saw blades. |
Photos
(5 cm)
(1 mm)
Sources
[1] Wikipedia
[2] Specimen from my personal collection, photo taken by me.
