Diamond formed at incredible depth shows evidence of radioactive fluids in cavities surrounded by green fluorescence halos.

The February 2012 discovery of high-quality blue sapphires at Thammannawa near Kataragama in southeastern Sri Lanka has intensified gem mining and exploration in the surrounding area and all over the country.

Offers a comprehensive look at a variety of augite from Dong Nai, Vietnam, detailing its formation and gemological characteristics.

An unusually large cultured pearl was filled with multiple cultured pearls, perhaps after the emergence of an original single-bead nucleus.

A report from the 34th IGC, held in Vilnius, Lithuania in August 2015.

The Stayish mine in Ethiopia’s Wollo province has been producing black opal since 2013.

The author examined a 0.56 ct Fancy grayish bluish green diamond with prominent green radiation stains.

A rare spinel, featuring a Star of David pattern and multiphase inclusions, is examined in Bangkok.

Topaz is an important gemstone that occurs in various colors.

Examination of a 0.40 ct near-colorless round brilliant diamond with a large inclusion resembling a dumbbell

A report on the color treatment process for these intensely greenish yellow to yellowish green cultured pearls and the techniques for identifying them.

An HPHT-treated round brilliant diamond with an inscription that presents as a GIA report number is found to be inconsistent with the institute's report, previously issued for an untreated diamond.

Observing a water drop’s interaction with opal, as well as refractive index, can confirm a specimen’s hydrophane nature with less risk of breakage than total immersion.

An opal rough is immersed in water and treated with oil and Opticon to observe effects on transparency and play-of-color.

A large natural pearl discovered in an edible oyster offers insight to the scientific pearl community.

The centerpiece of this brooch is a 98.67 ct Melo pearl, believed to be one of the world's largest.

Transparent rhodonite is considered one of the most difficult of all gems to facet because of its perfect cleavage and brittle, uneven fracture.

The distinction of natural from cultured pearls traditionally has been based on X-radiography.