Natural Colorless Type IaB Diamond with Silicon-Vacancy Defect Center
Examination revealed a rare instance of a silicon-vacancy defect in natural diamond.
Spinel Inclusion in Spinel
Examination of a pink-purple spinel revealed what appeared to be a spinel crystal inclusion.
Mixed-Type HPHT Synthetic Diamond with Unusual Growth Features
Although this stone bore some superficial resemblance to moissanite, its gemological properties were consistent with HPHT synthetic diamond.
Lead-Glass-Filled Burmese Rubies
Beads from a multi-strand necklace were the first examples of lower-lead-content glass filling in Burmese rubies examined at GIA’s Carlsbad laboratory.
Natural Pearl Aggregates from Pteria Mollusks
Ten loose pearls with interesting shapes and internal growth features were from Pteria-species mollusks.
CVD Synthetic Diamond with Fancy Vivid Orange Color
Strong absorptions from N-V centers were the main cause of a CVD synthetic diamond’s pinkish orange bodycolor.
Very Large Irradiated Yellow Diamond
A very large diamond with a Fancy Vivid yellow color was identified as artificially irradiated.
Screening of Small Yellow Diamond Melee for Treatment and Synthetics
Melee diamonds can be efficiently screened for synthesis and treatment using infrared absorption spectroscopy, DiamondView imaging, and microscopy.
A Larger, Higher-Quality NPD Synthetic Diamond
GIA’s New York laboratory recently detected an undisclosed NPD synthetic diamond, a 1.51 ct Fancy Black round.