
Unusual Absorption in a Blue Flux-Grown Synthetic Sapphire
The Bangkok lab identified unexpected characteristics in a flux-grown synthetic sapphire.

Baroque-Era Rose Cuts of Colored Stones: Highlights from the Second Half of the Seventeenth Century
Offers a systematic evaluation of rose cuts produced for various colored stones in the latter seventeenth century, based on the examination of rare artifacts that belonged to the archbishops and prince-electors of Trier and Cologne.

Large Type IIa Diamond from Arkansas, USA
The GIA lab in Carlsbad recently had the opportunity to examine a truly “all-American” diamond.

Largest CVD Laboratory-Grown Diamond Submitted to GIA
Progress in creating laboratory-grown CVD diamonds allows for larger sizes, including the largest yet seen at the Carlsbad lab.

Mineral Inclusions in Sapphire from Basaltic Terranes in Southern Vietnam: Indicator of Formation Model
Proposes a formation model for sapphire from the main deposits in southern Vietnam based on the chemical composition of their mineral inclusions.

Fluorescence Characteristics of Blue Amber from the Dominican Republic, Mexico, and Myanmar
Presents a combination of observational and spectroscopic means to separate the three main geographic localities for blue amber, which shows very strong blue fluorescence under sunlight or D65 illumination.

Low-Temperature Heat Treatment of Pink Sapphires from Ilakaka, Madagascar
Studies the effects of low-temperature heat treatment on inclusions in this gem material, as well as the use of FTIR spectroscopy to detect the treatment.
What Have Diamond Ages Taught Us?
Diamond ages offer insight into continent evolution spanning billions of years.
New Emerald Locality in Southern California
Located about 60 miles east of San Diego, a new emerald deposit has been discovered in the Julian Mining District.

Rhodium-Plated Iron Meteorites
The annual Tucson Gem and Mineral Show has been a reliable source for the niche and the unusual, as seen with the rhodium-plated iron meteorites acquired by author BL at the 22nd Street Show in February 2020.

Snowflake Inclusions in Mong Hsu Ruby
A holiday snowflake scene in a treated Mong Hsu ruby surprises and delights a gemologist in the Bangkok lab.

Artificial Glass Imitating a Paraíba Tourmaline
A creative imitation using fused bluish green glass with copper platelets poses as Paraíba tourmaline.

Metal Sulfide Crystal in a Sapphire
The combination of an iron sulfide crystal and a fingerprint enlivens the inclusion scene in a faceted sapphire from Sri Lanka.

Unmasking Emerald Filler
A long-wave ultraviolet flashlight illuminates chalky blue fluorescence in a fracture-filled emerald.

Oiled Tanzanite
A large tanzanite loses its appeal with the removal of its fracture-filling oil.

Irradiated Blue Diamond
Color engineering with artificial irradiation turns a pinkish purple Argyle diamond light blue.

Chromite Inclusions in Green Common Opal
Black opaque octahedral inclusions with yellow staining confirm the presence of chromite inclusions in an interesting common opal.

Blue Apatite in Pyrope-Spessartine Garnet
A garnet is cut and faceted to highlight its unusual inclusion.


Quarterly Crystal: Garnets in Aquamarine
Orange spessartine garnet inclusions are featured in this aquamarine recovered from the Shigar Valley in Pakistan.