Research Article Search Results
Growth Tube Cluster in Sapphire
Surface-reaching growth tubes in a sapphire provide insight into the gem’s origin and treatment history.
“Flower in the Rain” Inclusion in Sri Lankan Sapphire
A growth blockage/fluid inclusion combination in a blue sapphire from Sri Lanka resembles a bloom in a rainstorm.
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.
Colombian Emerald Industry: Winds of Change
A firsthand look at Colombia’s emerald mines and the cutting and trading industry in Bogotá.
The “Montana Queen” Sapphire
A rough blue sapphire crystal from the Rock Creek deposit is heat treated and cut to become the largest known faceted blue Montana sapphire.
Yellow, Green, and Blue Sapphires Reportedly from Antang and Gombe, Nigeria
Nineteen sapphires of various colors, reportedly from sources in northern Nigeria, are studied in GIA’s Tokyo laboratory.
The Unexpected Origins of Big Diamonds
Dr. Evan Smith, Ph.D., GIA research scientist, shares his findings on the unexpected origins of big diamonds and what their characteristics tell us about the earth.
The Latest on Synthetic Diamonds
Dr. James Shigley, GIA distinguished research fellow, is one of the foremost experts in diamonds and their identification. In this presentation recorded at the 2017 JCK Las Vegas show, he shares the latest developments about HPHT and CVD synthetic diamond
Carbonado Diamond: A Review of Properties and Origin
Presents a detailed examination of about 800 samples of carbonado diamond from Brazil and the Central African Republic, including possible models for its genesis.
Photoluminescence Mapping of Optical Defects in HPHT Synthetic Diamond
Demonstrates the importance of this method in identifying diamond treatments, based on the
analysis of PL maps acquired from a brownish orange HPHT synthetic diamond.
Big Sky Country Sapphire: Visiting Montana’s Alluvial Deposits
Documents a visit to the upper Missouri River and Rock Creek sapphire mining areas.
Chart: Inclusions in Natural, Synthetic, and Treated Sapphire
Provides a visual guide to the internal features of natural, synthetic, and treated sapphires.
