Spinel is found as an accessory mineral in some igneous rocks. It is also found with corundum in gem sands of Sri Lanka and in some metamorphic rocks. In the past, spinel has often been misidentified as ruby. This is not as difficult as you might think since they are very close in chemistry and color. One of the most famous misidentifications is the Black Prince's Ruby in the British Imperial Crown.
| MgAl2O4 |
|
| Oxide |
|
| Isometric |
|
| 4/m -3 2/m |
|
| 8 |
|
| 3.5-4.1 |
|
| None |
|
| Uneven |
|
| White, red, blue, green, brown, black, lavender |
|
| White |
|
| Vitreous |
|
| Tranlucent |
|
| Euhedral, granular |
|
| Notable Localities: |
New York; New Jersey; Sri Lanka; Thailand; Burma |
| Uses: |
Sometimes cut as a gem, mineral specimen |
| Corundum, pyrrhotite, graphite, phlogopite |
Specimens:
| |
