Observations on HPHT-Grown Synthetic Diamonds: A Review
Summarizes statistical data and distinctive features of several thousand gem-quality HPHT synthetic diamonds examined by GIA from 2007 through 2016.
Saltwater Pearls from the Pre- to Early Columbian Era: A Gemological and Radiocarbon Dating Study
Examines 85 saltwater natural pearls, reportedly harvested from the Caribbean islands off the coast of Venezuela during the early 16th century, to determine their age.
True Colors of “Dalmatian Jasper”
Discusses the mineralogical composition and provenance of this spotted decorative gemstone.
Unusual Cloud in Diamond
A diamond with a previously unseen clarity characteristic is seen in GIA’s Carlsbad lab.
Hematite in Quartz: “A Rose by Any Other Name”
A quartz cabochon hosts an unusual rose-shaped hematite inclusion.
Awards for James Shigley and Jonathan Muyal
Two regular G&G contributors receive awards for their work in the field of gemology.
Colombian Emerald Industry: Winds of Change
A firsthand look at Colombia’s emerald mines and the cutting and trading industry in Bogotá.
Synthetic Star Sapphires and Rubies Produced by Wiede’s Carbidwerk, Freyung, Germany
Details the process used by Wiede’s Carbidwerk to produce star synthetic corundum from the mid-1950s through the 1970s.
Letters: Note on CVD Synthetic Overgrowth
A response to the Summer 2017 Lab Note on CVD synthetic overgrowth on a natural diamond.
Photoluminescence Spectra of Emeralds from Colombia, Afghanistan, and Zambia
Compares PL spectroscopy data of 48 emerald samples from three countries to evaluate the usefulness of the technique in geographic origin determination.