Pearls, black opal, and chocolate diamonds are highly sought after gems. Many factors determine their value, including colors and sizes.

Opals are one of October's birthstones, and we round up the best luxury opal rings, bracelets, earrings, and necklaces in honor of the beautiful gemstone.

Black and white opals thrived during the Art Nouveau era, when René Lalique created several opal jewelry designs for actress Sarah Bernhardt.

Gemstones, including rubies, emeralds, and sapphires, can be sold for cash, much the same as diamonds and other jewelry.