News & Articles

Unusual Corundum Doublet

An Unusual Corundum Doublet

August 12 2016

Summary of ‘A Lead-Glass-Filled Corundum Doublet’ by Supparat Promwongnan, Thanong Leelawatanasuk and Saengthip Saengbuangamlam.

This Gemmological Brief describes a 1. …

Bruce Cleaver

Cleaver Appointend De Beers CEO

August 12 2016

Bruce Cleaver was announced as the new CEO of De Beers, effective July 1, 2016.

He assumes the role from Philippe Mellier, who had been CEO of the mining group for five ye…

Sapphire and diamond ring

Coloured Stone Guide – Sapphires

August 12 2016

So what is sapphire?
Sapphire and ruby are basically the same stone, corundum, which, as we saw, is comprised of aluminium and oxygen. The difference with sapphire though is that …

Rough Emerald

Coloured Stone Guide – Emeralds

August 12 2016

Belonging to the beryl family
 The third stone in this series on the more well-known (and sometimes lesser known) gemstones covers emerald. In the same way as ruby and sapphire w…