Fake Tridacna Pearls
Fake pearls are beads (of whatever shape) which have been cut entirely from shell material. A perfect source for the production of such fake pearls is the Tridacna clam, amongst the largest living bivalve mollusc with a massive and thick shell of up to 110 cm diameter, mainly living along shallow coastal water
Neutron and X-Ray Tomography of Emeralds
Since two years, the SSEF has been working with the Laboratory for Neutron Scattering and Imaging at the Paul Scherrer Institute (PSI) using their ICON beamline (cold neutron imaging) at the SINQ spallation source. The aim of these research projects in collaboration with Dr. Lehmann and Dr. Mannes is to analyse
Rarities and Collector Stones Tested at SSEF
The daily routine at SSEF usually consists of testing rubies, sapphires, emeralds, pearls and diamonds. Although sometimes challenging and interesting, especially taking into account the quality and the documented historical provenance of some of these gems and jewellery items, it is also always of great intere
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.
Rubies with Oil in Fissures
Over the past few years, the SSEF has repeatedly seen gemstones (apart from emeralds) which contained fissures filled with oil or other fillers. These include rubies, sapphires, spinels, tourmalines, garnets and even rarities such as pezzottaite.
The historic ‘Sleeping Lion Pearl’, a natural Blister and not a Pearl
Recently, the Swiss Gemmological Institute SSEF had the opportunity to investigate an impressive natural nacreous formation with documented provenance dating back to the late 18th century, named the ‘Sleeping Lion Pearl’ due to its baroque shape that is reminiscent of a lion.
Exceptional Spessartine Garnets
first published in Facette 21 (February 2014) In 2013, […]
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 2 […]
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