gemology

Value in colored gemstones is driven primarily by color, size, clarity, origin, and treatment status. For rubies, saturated red to slightly purplish red hues, often described as...

Jade commonly refers to two distinct minerals: jadeite and nephrite. Both are tough, fine-grained rocks valued for their durability, polishability, and even coloration, yet they...

The Elizabeth Taylor 68-carat diamond is a Golconda-origin Type IIa diamond known for its large size, cushion-modified cut, and vivid blue color. Purchased by Richard Burton for...

European cut diamonds refer to antique and older-style brilliant cuts generally pre–1930s, characterized by a taller crown, smaller table, open culet, and thicker girdles. The...

Opalite is a man-made glass-like material marketed as a decorative stone that resembles common opal or moonstone in appearance rather than a natural gem material with defined mi...

The world’s largest cut diamond is the Golden Jubilee Diamond, a 545.67‑carat fancy brown diamond that was cut and polished in Thailand. Originally a 755.5‑carat rough sto...

Diamonds are naturally occurring minerals made almost entirely of carbon, crystallized under high pressure and temperature deep in Earth’s mantle. Valued for exceptional hardn...

The largest pink diamond widely recognized in the transparent public and auction markets is the Pink Star (formerly the Steinmetz Pink), a type IIa rough gem weighing 59.60 cara...

Onyx brimstone is a phrase sometimes used to describe a dark, banded variety of sulfide mineral with a deep black appearance and a vitre to resinous luster. In geological and co...

The phrase Heart of the Ocean diamond usually refers to the fictional blue diamond in the 1997 film Titanic, yet audiences often ask whether a real gem inspired the story and wh...