GemTOF Analyses of Sapphires from Madagascar and Kashmir
In the beginning of 2017, gem testing laboratories started to receive cut stones from a new area for gem analysis and issuing reports. As stated in a trade-alert by SSEF in early 2017, some of this new sapphire material may resemble internal features of Kashmir blue sapphires, therefore careful microscopic inve
New Beads in Cultured Pearls
by Dr. Laurent E. Cartier, first published in Facette 21 (February 2014) We were presented with samples of a new type of pearl product from French Polynesia by a pearl trader during the 2012 BaselWorld show. These cultured pearls had unusual shapes, came in large sizes (up to 23 mm) and were characterised by
Corroded Pearls
by SSEF, first published in Facette 20 (January 2013) Although pearls, as organic gems, are commonly less stable than polished gemstones, we don’t often see pearls with obvious features of surface damage as a result of unfortunate care. A few months ago, however, we received for testing a very spectacular ca
Exceptional Colour Change Garnets Showing the Usambara Effect
by Dr. M.S. Krzemnicki, first published in Facette 21 (February 2014) Colour change, also known as“alexandrite effect” has been studied extensively since it was first described in 1831 for alexandrite (chromium-bearing variety of chrysoberyl) from Russia (von Pott, 1842). Since then, numerous minerals or g
Sapphires from Ambatondrazaka, Madagascar
Madagascar, an island of many gem treasures, saw in recent months another ‘sapphire rush’ after the discovery of a new gem deposit about 35 km east of the small town of Ambatondrazaka.
Sapphire from Andranondambo, Madagascar
first published in Facette 22 (February 2016) In 2016, the SSEF received a sapphire of exceptional quality and size for testing (Figure 1). The sapphire of 33 ct was characterised by a saturated blue colour, – poetically also known as royal blue and a highly attractive velvety appearance due to submi