An Era of Sweeping Change in Diamond and Colored Stone Production Markets
The diamond, colored stone, and pearl businesses have witnessed unprecedented change since the turn of the 21st century.
Diamond Within a Diamond Within a Diamond
A natural diamond contains two inclusions resembling a faceted diamond and a rough diamond.
Iridescent Pen Shell
Aragonite and calcite create a captivating iridescent effect in a Pinnidae shell.
Characterization of Colorless Coated Cubic Zirconia (Diamantine)
Over the past several years, diamond simulants have entered the market that consisted of colorless cubic zirconia reportedly coated with a thin layer (e.g., represented to be 30–50 nm) of nanocrystalline diamond particles embedded in a matrix.
“Paraíba”-Type Copper-Bearing Tourmaline from Brazil, Nigeria, and Mozambique: Chemical Fingerprinting By LA-ICP-MS
Gem-quality bright blue to green “Paraíba”-type Cu-bearing tourmaline is now known from deposits in Africa (Nigeria and Mozambique), in addition to three commercial localities in Brazil (in Paraíba and Rio Grande do Norte States).
Anahí’s “New” Ametrine
The Anahí mine in southeastern Bolivia has enjoyed consistent production since 1990 and is best known for its ametrine.
Gray-To-Blue-To-Violet Hydrogen-Rich Diamonds from the Argyle Mine, Australia
The Argyle diamond mine is the only known source of type IaB hydrogen- and nitrogen-rich diamonds colored gray to blue to violet.
Aquamarine from the Thuong Xuan District, Thanh Hoa Province, Vietnam
Vietnamese aquamarine is notable for its attractive color and well-formed crystals.
Glassy Melt Inclusions in Sapphires from Montana
Two-phase inclusions are investigated in alluvial sapphires from deposits in Montana.
Emeralds of the Panjshir Valley, Afghanistan
With the withdrawal of Soviet troops from Afghanistan, villagers in the Panjshir Valley are turning their attention to the emerald riches of the nearby Hindu Kush Mountains.
Abstracts; Spring 1994
This article, from the Spring 1994 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.
The Anahí Ametrine Mine, Bolivia
The Anahí mine, Bolivia, has produced large amounts of amethyst, citrine, and amethyst-citrine for the gem 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.
The Santa Terezinha De Goias Emerald Deposit
The author has uncovered many ancient references to the simulation or enhancement of gemstones.
Known Non-Nacreous Non-Bead Cultured Pearls and Similar Unknown Pearls of Likely Cultured Origin from Pinctada maxima
Natural Shell Blisters and Blister Pearls: What’s the Difference?
GIA researchers explore the differences between whole, blister, and shell blister pearls in this study using 33 samples from Pinctada maxima mollusks recovered off Broome, Australia.
Freshwater Pearls vs. Saltwater Pearls: Understanding the Difference
Quarterly Crystal: Cinnabar in Fluorite
Trigonal cinnabar inclusions are identified in a crystal cluster of fluorite and calcite.
Flux-Induced Fingerprint Patterns in Synthetic Ruby: An Update | Gems & Gemology
Some manufacturers are known to have treated Verneuil flame-fusion synthetic rubies by immersion in a flux melt to induce patterns like the “fingerprints” seen in some natural rubies.
Unusual Cloud in Diamond
A diamond with a previously unseen clarity characteristic is seen in GIA’s Carlsbad lab.
.jpg "YMAL GIA Ed")
