CVD Diamonds with Invisible Markings
A new type of invisible marking in CVD diamonds suggests a possible security measure.
Glass Imitation of Cat’s-Eye Chrysoberyl
A brownish yellow cabochon submitted as cat’s-eye chrysoberyl is identified as artificial glass.
Pink Zektzerite
A rare example of faceted gem-quality zektzerite is examined in GIA’s Carlsbad laboratory.
Plastic Imitations of Emerald
Two items submitted as emerald to the New York lab are identified as plastic manufactured products.
Separation of Black Diamond from NPD Synthetic Diamond
Yellow Synthetic Diamond with Nickel-Related Green Fluorescence
Metal Sulfide in Pyrope
Analysis reveals a surprising component to a metal sulfide inclusion in garnet.
Rare Type IIb Gray-Purple Diamond
A natural type IIb diamond with rare color and very strong 776.4 nm PL peak is seen at the Carlsbad lab.
Purple Scapolite
2015 Sinkankas Symposium
Opal was the focus of the April 2015 Sinkankas Symposium at GIA’s Carlsbad, California campus.
An Unusual Filled Ruby
African Rhodochrosite and Colombian Quartz with Trapiche Patterns
An eclectic grouping of gems and minerals at Tucson’s Pueblo show includes South African and Colombian specimens.
Kämmererite Cabochons from India
Macedonian Ruby Specimens
Ruby cabochons from mainland Europe’s only deposit are available on the market.
Synthetic Moissanite Imitations of Synthetic Colored Diamonds
Chalcedony Beads Coated With Titanium Nitride
Beads in an necklace show a metallic appearance not seen in chalcedony.
New Deposits of Gem-Quality Common Opal from Michoacán, Mexico
Material from a new opal deposit in Morelia, Mexico is examined.
Raspberry-Red Garnet with Black Core
Chemical analysis is performed on the black core of a red grossular garnet crystal.
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