Characterizes turquoise treated with an inorganic additive that dramatically improves the luster and color of low- and medium-quality material.

Examination of a yellowish green demantoid reveals fibers of serpentine in a randomly curved pattern and a columnar two-phase negative crystal.

The Carlsbad laboratory reports on a Fancy Deep brownish yellowish orange diamond featuring trigons within subsurface etch channels.

Fiber-optic illumination reveals an electromagnetic wave-like pattern of particles in a ruby from Myanmar.

Examines the use of strong fluorescence near 394 nm under 320 nm excitation as a potential means of identifying copper diffusion treatment of feldspar.

A field gemology team from GIA provides an update on the ruby mining operations around Montepuez.

Rose channels and twinning planes are observed in light purplish blue synthetic corundum.

A detailed spectroscopic investigation of the color of pink spinel reportedly from the Kuh-i-Lal deposit in the Pamir Mountains of Tajikistan.

The Tokyo laboratory examines a Paraíba tourmaline with chatoyancy caused by copper inclusions.

A comprehensive look at the gemological features and advanced analysis of blue and fancy-color sapphire from the agricultural area of Muling, China.

A report on the first-ever Turquoise United conference in Albuquerque, New Mexico.

Explores the use of gem materials as pigments in works of art, from the earliest cave paintings to the modern era.