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Geographic Origin Determination of Paraíba Tourmaline
Copper-bearing gem tourmaline, known as Paraíba tourmaline after the location of its original discovery, is prized for its vivid blue to green color. This article explains GIA’s use of quantitative chemical analyses to distinguish samples from Brazil, Nigeria, and Mozambique.
Natural Rubies with Glass-Filled Cavities
Novelty Cut Diamond with Remarkable “Fire and Ice” Fluorescence
Fraudulently Inscribed Synthetic Moissanite
The Mumbai laboratory finds a fraudulent GIA inscription on synthetic moissanite.
Polymer-Filled Aquamarine
Eclogite: Diamond-Encrusted Ancient Seafloor
Explores eclogitic diamonds, which make up a significant portion of the gem diamond market, and what they reveal about Earth’s dynamic processes.
Demantoid Garnet Fossil Pseudomorphs
CVD Laboratory-Grown Diamond with Counterfeit GIA Inscription
A CVD laboratory-grown diamond with a fraudulent GIA inscription is submitted to the Antwerp lab.
Known Non-Nacreous Non-Bead Cultured Pearls and Similar Unknown Pearls of Likely Cultured Origin from Pinctada maxima
Extraordinary Large Bicolor Natural Rough Diamond
A 37.41 ct natural rough diamond with distinct pink and colorless zones is examined at GIA’s Botswana laboratory.
How GIA Analyzes Pearls from Start to Finish
GIA is a trusted authority known for its rigorous, objective analysis of both natural and cultured pearls. Learn about how GIA analyzes pearls here!