Gemstones in the Era of the Taj Mahal and the Mughals
A look at the gem ornamentation of this landmark, as well as the jewels of the Mughal dynasty.
Natural-Color Fancy White and Fancy Black Diamonds: Where Color and Clarity Converge
A systematic study of the properties of approximately 500 Fancy white and 1,200 Fancy black diamonds.
Hydrogen-Rich Green Diamond Color-Treated by Multi-Step Processing
Characterization of an intense yellowish green faceted diamond revealed a complex treatment process.
Effects of Mollusk Size on Growth and Color of Cultured Half-Pearls from Phuket, Thailand
Determines methods for maximizing production and quality of cultured half-pearls.
Pressed Gibbsite and Calcite as a Rhodochrosite Imitation
Examines a new rhodochrosite simulant composed of pressed gibbsite and calcite powder.
Characteristics of Hydrothermally Treated Beeswax Amber
Reveals the process for hydrothermal enhancement of amber and the means of detection.
2019 GSA Annual Meeting
Research topics covering diamonds and colored stones were presented at the annual meeting of the Geological Society of America in Phoenix, Arizona.
Merelaniite in Gem Diopside from Merelani, Tanzania
Fine merelaniite whiskers discovered in gem-quality yellow-green diopside crystals.
Gem Art of the Taj Mahal, Fancy White and Black Diamonds, and Unique Inclusions in Thai Corundum
An overview of the Fall 2019 Gems & Gemology content.
Grossular Garnet Crystals in Demantoid Garnet
Demantoid garnet plays host to crystals of a different garnet species.
Natural Sapphire with Trapiche Pattern Inclusions
Arrays of hexagonal particle inclusions resemble a trapiche pattern in this natural sapphire.
Uvarovite in Prehnite from Pangasinan Province, Philippines
Vibrant green uvarovite garnet in a white prehnite matrix with lapidary potential discovered in the Philippines.
Fall 2019 G&G Publication Information
This document provides the publication information for Gems & Gemology
Conichalcite in Quartz Chalcedony
Vibrant yellowish green conichalcite inclusions seen in chalcedony for the first time by the Carlsbad laboratory.
Emerald in Rock Crystal Quartz
Perfectly hexagonal emerald crystal identified within a gem-quality rock crystal quartz.
Phenakite with Tourmaline Inclusion Containing Spiral Growth
A phenakite specimen from Madagascar revealed an eclectic inclusion scene containing tourmaline and other crystals.
Rain Cloud in Alexandrite
Milky particles and bands of silk resemble a rain cloud in this faceted alexandrite.
Tourmaline Inclusion in Russian Alexandrite
Russian alexandrite hosts well-formed prismatic tourmaline inclusions, a rare combination worthy of a collector’s specimen.
Recrystallization of Baddeleyite as an Indicator of PHT (“HPHT”) Treatment in Sapphire
High baddeleyite content in heated sapphire may signal PHT (“HPHT”) treatment.
Johnkoivulaite: A New Gem Mineral
A new mineral, johnkoivualite, named after prominent GIA gemologist and photomicrographer.