A gemmologist’s delight: poudretteite, musgravite, taaffeite, and grandidierite
by Dr. M.S. Krzemnicki, first published in Facette […]
Two exceptional asteriated diamonds
by Dr. L. Speich & J.-P. Chalain, first published i […]
Heated ruby from Mong Hsu (Myanmar) with blue zone
Rubies from Mong Hsu, located about 250 km southeast of the Mogok Stone Tract, entered the gem trade in the early 1990s. Since this time the Mong Hsu mines remain an important source for Burmese rubies, specifically for stones of smaller sizes (2 ct and below).
New pearl oyster species: pinctada persica
We recently tested a pearl jewellery set that consisted of 63 natural pearls, with 61 of them being strung on a thread and two additional loose natural pearls. To our knowledge, this is the first time that pearls from Pinctada persica have been reported.
Age dating of cobalt spinel
Radiometric U-Pb dating is a promising tool in gemstone testing and is used at SSEF as an advanced analytical procedure since several years. However, this method is usually only applicable when the gemstone presents sufficient traces of radiogenic elements either in its crystal structure or within a solid inclu
Colour varieties of gems – where to set the boundary?
by Dr. M.S. Krzemnicki, first published in Facette 26 ( […]
Talisman of Charlemagne
by Dr. M.S. Krzemnicki, first published in Facette 26 ( […]
Update on unheated Mozambique rubies
by Dr. M.S. Krzemnicki, first published in Facette […]
