Vietnam is a land of great diversity and beauty. From the hustle and bustle of Ho Chi Minh City to the beauty of Hạ Long Bay and Hoi An (both UNESCO World Heritage Sites), there are innumerable places ...

Figure 1. This gold ring with a phoenix motif features a Neyshabur turquoise (13 × 17 mm), with a 0.02 ct ruby on each side and diamond accents. Courtesy of Taktala Jewelry, Tehran. Turquoise is an ...

Contact-twinned crystals of natural diamond rough, known as “macle,” typically exhibit a flattened triangular shape, which has been attributed to preferential growth at re-entrant corners where two ...

Rough pink diamonds are rarely found, and although the cause of color has been correlated with plastic deformation, the precise mechanism and atomic configuration for the resulting color are topics of ...

The Karowe Diamond Mine in Botswana, owned and operated by Lucara Diamond Corp., has gained international recognition for producing large, high-quality type IaB or coexistence of IaB with IIa diamonds ...

CARLSBAD, Calif. – June 2, 2025 – Beginning later this year, GIA (the Gemological Institute of America) will start using descriptive terms to characterize the quality of laboratory-grown diamonds and ...

Figure 1. Sapphires from Madagascar: a beautiful 3.29 ct untreated faceted stone and an assortment of rough in the background. Madagascar has produced many high-quality stones in the last few years ...

Diamonds have a long history as a premier gemstone—a natural consequence of their beauty, rarity, and superlative physical properties such as extreme hardness. Diamonds that are mined for use as ...

Australian emeralds have been known for over a century but have always maintained a low profile. Small volumes, low clarity, and desaturated color were among the reasons for their lack of recognition ...

The micro-world of gems lies at the very core of gemology. Information gathered from observations through the microscope serves as the very foundation for many conclusions drawn on a specimen, ...

Earth’s surface is divided into tectonic plates, and the ones that make up the ocean floor are destined to sink. Sheets of oceanic crust typically bend and sink down into Earth’s interior at so-called ...

In November 2022, a parcel of 24 approximately 0.5–1.2 ct spinel crystals, described as cobalt-diffused, were obtained directly from a treater by the research team at GIA in Bangkok. Of these, seven ...