Reports on the geology, background, and current state of mining and production at Iran’s largest turquoise mine.

Figure 1. The vivid colors seen in fine gem-quality spinel are derived from the mixing between multiple different chromophores in a range of ratios and concentrations, as in this fine 13.52 ct violetish purple spinel. Courtesy of the Dr. Edward J. Gübelin Collection. Photo by Robert Weldon/GIA.

A selection of 74 non-bead cultured and 12 bead cultured pearls grown in cultured pearl sacs and harvested directly from operated mollusks were collected and their internal structures examined using real-time microradiography and X-ray computed microtomography analyses.

Extensive analysis of early beads and pendants from archaeological sites in the French islands of the Lesser Antilles identified the objects as sudoite, which has never before been documented in any lapidary production.

Although spinel is rarely treated, there have been some heated spinels available in the trade.

A colorless topaz from Nigeria hosts the only known example of willemite as an inclusion in topaz.

The Tokyo lab examined a stunning double cat’s-eye emerald whose chatoyancy was created both by its cut and its inclusions.

A group of large, high-quality CVD material demonstrates the continued challenge of identifying laboratory-grown gems.

Creative faceting highlights an octahedral-shaped cloud inclusion in a 2.01 ct diamond octahedron.

The Carlsbad laboratory recently had the chance to examine a 4.60 ct cushion-cut zircon with truly unusual color behavior.

Careful comparison of two GIA reports reveals a fraudulent inscription on a laboratory-produced diamond presented as a natural.

Recently, a 23.67 ct pear cabochon aquamarine with light greenish blue color and poor clarity was sent to the Taiwan Union Lab of Gem Research (TULAB) for identification.

This study examines FTIR spectra of yellow sapphire heat treated in an oxidizing atmosphere to deepen its color.

Fura Gems hosted its first sales event for rough Mozambican rubies in August and September 2021.

A study on heat with pressure treatment of blue sapphires reveals FTIR patterns associated with different iron concentrations.