Corundum var Sapphire

In the early 19th century exploitation of the K Feldspar/Corundum rich Ilmeny Mountains began. Corundum crystals up to 40cm were found. In the late 1990’s another deposit was found near the town of Miass. It is likely this specimen is from that later discovery. This specimen contains hexagonal bluish crystals to 3cm across. I count at least 9 distinct corundum crystals. Ex Mike Wortham.

Locality: Ilmeny Mountains, Chelyabinsk Oblast, Southern Urals Region, Russia

Composition: aluminum oxide in potassium feldspar