2 ms·
Sapphire crystal [1] is something like transparent aluminum rust. Alumina [2] is too, I think. They might be the same thing, I'm not a chemist. [1] https://en.
by stephengillie 11y ago
Sapphire crystal [1] is something like transparent aluminum rust. Alumina [2] is too, I think. They might be the same thing, I'm not a chemist.
[1] https://en.wikipedia.org/wiki/Sapphire https://en.wikipedia.org/wiki/Sapphire
[2] https://en.wikipedia.org/wiki/Aluminium_oxide https://en.wikipedia.org/wiki/Aluminium_oxide
- Florin_Andrei 11y agoSapphire and ruby are both aluminum oxide - i.e. 'alumina' - just with different kinds and amounts of impurities. Yes, it is technically the stuff you get when you throw aluminum powder over a fire and it lights up and burns brightly. But the crystals you obtain that way are very tiny.
- gjmulhol 11y agoAlumina is Al2O3 generally, and usually it is polycrystalline. Sapphire is specifically Al2O3 in a certain (very hard) crystal structure.