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 ...

CARLSBAD, Calif. – November 4, 2024 – The GIA laboratory in Ramat Gan, Israel, will end operations by the end of 2024 due to changes in the global diamond industry that resulted in significant ...

Figure 1. This cross section through ancient thickened continental lithosphere and underlying mantle shows the two major depth intervals of diamond formation. The majority of mined diamonds originate ...

Jadeite jade is one of the most important aggregate gems in today’s global marketplace, with known sources in Myanmar, Japan, Russia, and Guatemala. Among them, Myanmar is the most legendary and still ...

A well-known collector mineral, wavellite (Al 3 (PO 4) 2 (OH) 3 •5H 2 O), is named after its discoverer, British surgeon Dr. William Wavell. Wavellite mineral specimens seen on the market often occur ...

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 ...

Carved single-crystal diamond rings are rare, with few examples to reference (see Spring 2020 Lab Notes, pp. 132–133). But with advancing technology in the laboratory-grown diamond industry, the ...

Since the introduction of its new digital Laboratory-Grown Diamond service, GIA has recently seen a vast increase in the number of diamonds grown by chemical vapor deposition (CVD). These are often ...

Feature Gems & Gemology, Summer 2021, Vol. 57, No. 2 Detection of Color Treatment and Optical Brightening in Chinese Freshwater “Edison” Pearls Chunhui Zhou, Joyce Wing Yan Ho, Sally Chan Shih, ...

Several vendors at both the AGTA and GJX shows carried large and attractively colored “Edison” pearls from China (see C. Zhou et al., “ Detection of color treatment and optical brightening in Chinese ...

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 ...