Only during the last few years have the gem riches of Pakistan become known to the rest of the world. This article reports on three gem materials currently being mined: emerald, corundum (most ...

Diamond is available in a range of sizes and qualities to fit every consumer's tastes. One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, ...

The Republic of Mozambique is located in southeastern Africa along the Indian Ocean. Separated from Madagascar by the Mozambique Channel, it is bordered by Tanzania to the north, South Africa to the ...

There is only one known commercial occurrence of gem-quality red beryl in the world: the Ruby Violet (or Red Beryl) mine in the Wah Wah Mountains of Beaver County, Utah. The beryl is found mostly ...

This note deals with some gemological applications for a tool well known to microscopists: the first-order red compensator. In gemological microscopy, the compensator can be useful in locating ...

The authors present the mineralogical and gemological properties of rubies found recently in the Morogoro area of Tanzania that have many features in common with rubies from Myanmar (Burma) and other ...

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 ...

Gem-quality synthetic or laboratory-grown diamonds are more available in today’s jewelry marketplace than ever before, causing both interest and concern about lab-grown diamonds and whether ...

Gem inclusions are mineral crystals or cavities filled with fluid and/or gas that occur in a host gemstone. Many gems contain microscopic inclusions (ranging in size from >1 mm down to submicroscopic ...

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 ...

Diamonds are known for their hardness – their ability to resist scratches and abrasions. But diamonds are not impervious to damage, since their hardness is uneven along different crystal directions.

Terry Coldham (left) and Jack Wilson (right) each have more than 50 years of experience in Australian sapphire mining and trading. They shared their in-depth understanding of the Australian sapphire ...