Gemstones are valued based on the Four Cs - color, clarity, cut, and carat. Precious stones include diamonds, sapphires, rubies, and emeralds. Semi-precious stones are evaluated on their rarity and ...

Gemstones are treasured for their exquisite beauty, sentimental symbolism and—perhaps most importantly—their market value. These precious pieces of rare rock, once polished and cut, can be worth tens ...

The international gem trade can be a shady business. In a quiet corner of a busy London pub, a trader, who asked to remain anonymous, tells C&EN about passing off synthetic gems, made in a ...