Marble Imitation of Jadeite Rough
A stone submitted as rough jadeite proves upon analysis to be marble, indicative of the increasing use of imitations in the jewelry market.
Purplish Pink Diaspore Reportedly from Afghanistan
Diaspore, an orthorhombic aluminum oxide hydroxide mineral with the formula AlO(OH), is a relative newcomer to the jewelry scene, with some stones possessing a captivating ability to change color between pale green, yellow, pink, and purple when viewed in different sources of light.
Summer 2020 G&G Publication Information
This document provides the publication information for Gems & Gemology
Portrait of a Paraíba Rough: Challenging Gems in Hard Times
Many variables were involved in the sale and manufacture of a beautiful rough gem during difficult times.
Cat’s-Eye Andradite
Fine needle inclusions create a striking cat’s-eye effect in a rare brownish yellow andradite garnet.
HPHT Laboratory-Grown Pink Diamond with Unstable Color
A lab-grown diamond with an equivalent color grade to Fancy Vivid pink demonstrates a temporary color change under short-wave UV radiation.
Rare Inclusion of Chabazite in a Precious Opal from Ethiopia
An inclusion rarely seen in a cut stone appears in a gray Ethiopian opal.
Trapiche-Like Pattern in an Emerald from Pakistan
Brightfield illumination reveals a distinctive growth pattern similar to trapiche in a beautiful emerald from Swat Valley.
HPHT-Processed CVD Laboratory-Grown Diamonds with Low Color Grades
The Antwerp lab examines CVD laboratory-grown diamonds where HPHT processing resulted in relatively low color grades.
A New Deposit of Pink Natrolite from Indonesia
Lovely rose-pink natrolite from Indonesia is dubbed “rhodatrolite” for its color and texture.
Exceptional Purple Montana Sapphire
A particularly fine unheated purple Montana sapphire is noted for both its size and its multiple diverse inclusions.
Hemimorphite Resembling Paraíba Tourmaline
Copper in the zinc silicate known as hemimorphite creates an electric blue color similar to that of Paraíba tourmaline.
Pink Mozambique Sapphire
Examination and testing of a beautiful large pink sapphire establishes its lack of treatment and its origin in Mozambique.
Irradiated Blue Diamond with Interesting DiamondView Image
DiamondView image of an irradiated blue diamond reveals unusual gemological features due to a combination of treatments.