Zircon inclusions in unheated pink sapphires from Ilakaka, Madagascar: A Raman spectroscopic study
Presentation at the online 2021 International Gemmological Conference by Dr. Michael S. Krzemnicki.
Raman spectroscopic investigation of zircon in gem-quality sapphire: Application in origin determination
Raman spectroscopic investigation of zircon in gem-qual […]
Low-Temperature Heated Rubies From Mozambique
by Dr. Michael S. Krzemnicki, first published in F […]
Emeralds and the Saga of Cleaning and Filling Fissures
There is a long established tradition in the trade to fill open fissures in emeralds with colourless fillers, such as oil, wax and (artificial) resins, to reduce their visibility. Disclosure of such treatments is mandatory (CIBJO), including a quantification of the filler substance, as this may have a direct im
Spinel from Mahenge (Tanzania) and its Heat Treatment
first published in Facette 22 (February 2016) In 2 […]
Fake Historic Provenance: ‘Aged ’ Cultured Pearls
Most recently, we received a pearl necklace with 410 pearls strung on three regularly graduated strands. The pearls were characterized by a beautifully matching colour and a fine pearl lustre, reminiscent of ‘classic’ natural pearls from the Arabian Gulf. However, a closer look using X-ray luminescence (SSE
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.
Sapphires Heated with Pressure – A Research Update
Sapphires Heated with Pressure – A Research Update. Pub […]
Cobalt diffusion-treated spinel
Cobalt diffusion-treated spinel. Published in IGC Namib […]
Emeralds and the saga of cleaning and filling fissures
Emeralds and the saga of cleaning and filling fissures. […]