Published in the GemGuide: Rarity of Tanzanite Nov/Dec Vol. 36, Issue 6

In 1967, blue-violet crystals of the mineral species, zoisite, were discovered south of Mount Kilimanjaro in northeast Tanzania. The host rocks of the discovery, which are orders of magnitude older than Africa’s highest mountain, form part of the Lelatema Mountains and are located very near to the town of Merelani.

GemGuide Cover Nov/Dec 2017

https://gemguide.com/the-gemguide/

Robert Gessner