Zircon Showing Asterism
first published in Facette 22 (February 2016) Martin St […]
Colour-Changing Zircon
by Dr. M.S. Krzemnicki, first published in Facette 20 ( […]
The Usambara Effect and other colour-change Effects in Gemstones
Colour change in gemstones is an interesting phenomenon, which can be due to a number of reasons. One of the causes is the so called Usambara effect, a type of colour change which is not so well known in the public. In contrast to the alexandrite effect, this phenomenon is not dependent on the type of illuminat
The Beryl Group – an Overview
The Beryl Group – an Overview. Published in Journal of […]
Purple Mozambique Garnet
In early 2016, attractive bright purple garnets arrived at SSEF in Bangkok, Basel and Hong Kong. Based on client information, they are from a new mine, Padagaga in the Chimoio area in Mozambique, which was discovered recently.
Exceptional Spessartine Garnets
first published in Facette 21 (February 2014) In 2013, […]
Exceptional Colour Change Garnets Showing the Usambara Effect
by Dr. M.S. Krzemnicki, first published in Facette 21 ( […]
Gemstones of the Garnet Group – about mixed crystals and solid solution
Gemstones of the Garnet Group – about mixed crystals an […]
Grossular from Tanzania with Uncommon Inclusions
Grossular from Tanzania with Uncommon Inclusions. Publi […]
Yellow danburite from Namalulu, Tanzania, and Myanmar: Origin of Colour and Its Stability
Yellow danburite from Namalulu, Tanzania, and Myanmar: […]