Examines samples of Mona Lisa turquoise to identify their chemistry and structure, revealing copper as a major elemental component of the material.

Reports on a new source of primary gem-quality sapphire from Montana, comparing its inclusions and trace element chemistry with those from secondary sources in the state.

A photo tour of the GIA Museum’s latest exhibit featuring extraordinary crystals and gems central to the cultures of southern Asia.

An overview of the Winter 2025 Gems & Gemology content.

Investigates deposits known for producing multiple gemstone species and the conditions that create their distinct geological settings.

GIA will launch redesigned colored stones reports and new services on January 1, 2026.

GIAは2026年1月1日、デザインを一新したカラーストーンレポートと新サービスを開始します。

A diamond octahedron from South Africa hosts a rare yellow-orange almandine-pyrope garnet crystal.

A study analyzing the thermal behavior of the 3161 cm^–1 IR feature in 10 natural corundum samples from various deposits.

Organic-rich material is observed through an opening in a hollow natural pearl.

A euhedral prismatic pargasite crystal is identified in pink spinel.

Natural pearl cores are used to simulate the appearance of natural pearl growth in two assembled pearls mounted in a pair of earrings.

A diamond ring from a claw game in Japan is analyzed.

Examination of a 1.34 ct ruby reveals a unique inclusion formed during heat treatment.

The Carlsbad lab receives a laboratory-grown colorless sapphire with weblike fractures containing concentrations of dye.

A combination of growth and dissolution features contribute to a yellow diamond’s unique shape.

Gersdorffite inclusions in quartz exhibit either triangular or hexagonal shapes when viewed from different directions.

A 63.17 ct dumortierite rough crystal is examined in the Bangkok laboratory.

Blue needle-like inclusions are analyzed in three quartz spheres.