Update on Dyed Hydrophane Opal
Opal purportedly from a new deposit is found to be dyed.
Summer 2016 G&G: Diamonds from Diavik, Responsible Sourcing and Fabergé Cossack Figures
A summary of the content found in the Summer 2016 issue of Gems & Gemology.
Hydrophane Opal Treatment
An opal rough is immersed in water and treated with oil and Opticon to observe effects on transparency and play-of-colour.
Coated Fire Opal in the Chinese Market
An investigation of a coated fire opal recently found in the Chinese market.
The first documented UV-reactive chemical treatment to make opal appear tenebrescent.
Water Immersion Reveals Dye in Fire Opal
A simple test easily detected dye treatment in fire opal.
A Useful Technique to Confirm the Hydrophane Nature of Opal
Observing a water drop’s interaction with opal, as well as refractive index, can confirm a specimen’s hydrophane nature with less risk of breakage than total immersion.
Treated Andamooka Matrix Opal
Matrix opal from Andamooka, in South Australia, is a precious opal-included porous rock that is commonly colour enhanced (carbon impregnated) to imitate the highly prized black opal from Lightning Ridge in northern New South Wales, Australia.
Abstracts; Summer 2009
This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
Abstracts; Winter 2009
This article, from the Winter 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.