Winza ruby with hollow tube as a helix
In late 2007, a new deposit of rubies was discovered near the village of Winza in central Tanzania, creating quite a stir in the trade due to the quality and vivid colour of these rubies.
Eclogitic orange-yellow diamonds coloured by the 480 nm band
We recently acquired three orange-yellow diamonds for the SSEF collection research. These diamonds immediately retained our attention when we did the UV-vis-NIR spectra to identify the defect at the origin of their colour.
Old cultured pearl necklaces
Recently, the SSEF received three pearl necklaces for testing. Each necklace had a clasp containing diamonds and what appeared to be a sapphire. The pearls were graduated in size, with a small knot separating each one.
Fissure filling in spinel
The practice of filling fissures with a colourless substance, such as oil, wax or artificial resin, has been common in the gemstone trade for many decades, if not centuries.
Bachelor thesis on heated blue zircon from different origins
Zircon (ZrSiO4) is a common accessory mineral found in rocks, as well as an inclusion in gemstones, primarily corundum. Zircon is also known as a gemstone in its own right, either colourless or in many attractive colours, the most popular of which is blue.
Spectrofluorometer: New instrument at SSEF
We have acquired a new instrument at SSEF: a JASCO FP-8550 spectrofluorometer. A spectrofluorometer is a device that can measure fluorescence excitation and emission spectra.
SSEF GemTrack: Documenting the journey of a gemstone
Launched in 2019, the SSEF GemTrackTM service is asked by more of our clients every year. This tracking service not only documents the journey of a gemstone in time, but is also an attractive option for our clients to tell the story of the provenance of a specific and exceptional gemstone to their cu
An uncommon artificial resin feature in a brazilian Paraiba tourmaline
Recently, we examined a vibrant Brazilian Paraiba tourmaline weighing approximately 6 carats. One particular internal feature stood out that we found interesting for sharing.
CVD synthetic diamond with colour shift
Last November, the SSEF received an interesting round brilliant colourless (with a greyish tint) diamond of ca. 0.7 ct. mounted on an earring for testing.
Emeralds from the Minas Canaã, Minas Gerais, Brazil
In September 2024, the SSEF had the privilege of testing a few emeralds from the Mina Canaã, some of which exhibited exceptional qualities. Impressive in terms of weight, clarity and colour, these stones had further been spared any treatments, thus meaning their attributes were entirely natural.