Corundum is a crystalline form of aluminium oxide typically containing traces of iron, titanium, vanadium, and chromium. It is a rock-forming mineral. It is a naturally transparent material, but can h
Corundum from Brazil, size about 2 cm × 3 cm (0.8 in × 1 in)
Auguste Victor Louis Verneuil was a French chemist who invented the first commercially viable process for the manufacture of synthetic gemstones. In 1902 he discovered the "flame fusion" process, call