CARLSBAD, Calif. – August 26, 2025 – GIA, the Gemological Institute of America, will launch revised evaluation services for D-to-Z laboratory-grown diamonds on October 1. Current GIA laboratory ...

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 ...

Zambia is considered the world’s second most important source of emeralds by value (after Colombia). The deposits are located near the Kafubu River in the Ndola Rural Restricted Area. Emeralds have ...

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, ...

“Rabbit hair” quartz is a commercial variety of quartz with special inclusions. These inclusions resemble rabbit fur and are shorter and thinner than the typical rutile, tourmaline, or other acicular ...

Figure 1. A suite of nine rubies from the Rock Creek sapphire deposit in Montana. The stones range in weight from 0.172 to 0.578 ct. Photo by Kevin Schumacher, courtesy of Jeffrey R. Hapeman, Earth’s ...

At the AGTA show, we spoke with Alex Skachkov of Misfit Diamonds (Vancouver, Canada) about some of their unusual diamonds (figure 1). When asked what was popular, he showed us their aptly named “salt ...

Chemical vapor deposition (CVD) growth technology has advanced significantly over the last two decades. In this study, we report on the largest CVD gem diamond GIA has encountered, recently tested in ...

Zhushan County is the most abundant source of commercial turquoise in China’s Hubei Province, where mass production has been ongoing for several decades. Chinese turquoise production and consumption ...

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 ...

There are two types of high-pressure, high-temperature processes related to diamond: HPHT treatment and HPHT diamond growth. HPHT laboratory-grown diamonds were developed in the mid-1950s, with the ...