The science of gem testing at SSEF: a fascinating tale
Gemmology is a science with its foundations more than a hundred years ago, specifically driven by the emergence of synthetic stones and cultured pearls in the gem trade in the early 20th century.
Pair of sautoirs by René Lalique
René Lalique (1860-1945) was one of the most ingenious and creative designers of jewellery and glass objects at the end of the 19th and beginning of the 20th century. He significantly contributed to the Art Nouveau and Art Déco periods.
Gemmological study of the medieval Königsfelder diptychon
In 1298 AD, the king of Hungary Andreas II presented to his wife Queen Agnes a stone-set wooden altar piece as a royal wedding present. This small medieval artwork, known today as the Königsfelder diptychon, was originally made in Venice.
Souvenirs from the past: doublets uncovered at SSEF
From time to time, we get a flashback in gemmological history. This is specifically the case when we receive an antique ring with an ‘early’ Verneuil synthetic ruby showing strongly curved growth bands, or, as in the past few months, when clients submit us doublets.
A new led daylight source for diamond colour grading
In 2020, a novel light source for the colour grading of diamonds was developed in a collaboration between SSEF and the Department of Physics, University of Basel (see Figure 1). In contrast to many of the models on the market, the new light source uses state-of-the-art LED (Light Emitting Diode) lights instead
A gemmologist’s delight: poudretteite, musgravite, taaffeite, and grandidierite
by Dr. M.S. Krzemnicki, first published in Facette […]
Zircon inclusions in unheated pink sapphires from Ilakaka, Madagascar: A Raman spectroscopic study
Zircon inclusions in unheated pink sapphires from Ilaka […]
Colour varieties of gems – where to set the boundary?
by Dr. M.S. Krzemnicki, first published in Facette 26 ( […]
New statistical methods for analysis of gemstones
Based on real case studies on sapphire and emerald specimens, we here present how a simultaneous multi-element approach assists origin determination. Instead of pre-defining a list of isotopes in advance, routine analysis of blue sapphires using LA-ICP-TOF-MS detects rarely occurring trace elements such as bery
Deep purple vesuviatine from Pakistan
by Prof. H.A. Hänni, first published in Facette 26 (May […]