Pyrope Garnet and Montana Sapphires Highlight Winter 2015 G&G
G&G Brief presents an overview of the content of the Winter 2015 issue of Gems & Gemology.
Synthetic or Imitation? An Investigation of the Products of Kyocera Corporation That Show Play-Of-Color
An investigation of the difference between synthetic opal and opal simulant.
New Deposit of Black Opal from Ethiopia
The Stayish mine in Ethiopia’s Wollo province has been producing black opal since 2013.
Abstracts; Summer 2010
This article, from the Summer 2010 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.
Coated Fire Opal in the Chinese Market
An investigation of a coated fire opal recently found in the Chinese market.
An Opal-Calcite Composite
Gem Testing lab in Jaipur, India recently examined a white-brown, translucent to opaque oval cabochon that turned out to be a composite featuring an unusual combination of gem materials.
Chrysoprase and Prase Opal from Haneti, Central Tanzania
Commercial quantities of gem-quality chrysoprase and green prase opal (nickel-bearing chalcedony and common opal, respectively) have been recovered from altered serpentinite deposits near Haneti, Tanzania.
"Opalite": Plastic Imitation Opal with True Play-Of-Color
A plastic imitation opal that shows true play-of-color was advertised as "new" and offered for sale under the trade name "Opalite" at the Gem and Lapidary Dealers Association (GLDA) Tucson show in February 1988.
New Occurrence of Fire Opal from Bemia, Madagascar
Twenty-two gem opals from a new volcanic deposit located near Bemia
Treated Andamooka Matrix Opal
Matrix opal from Andamooka, in South Australia, is a precious opal-included porous rock that is commonly color enhanced (carbon impregnated) to imitate the highly prized black opal from Lightning Ridge in northern New South Wales, Australia.