Understanding Gem Jewelry

Sapphire, September's birthstone, has been the pre-eminent blue gemstone for centuries. Ancient Persian rulers believed its reflection painted the heavens blue. Indeed, its very name in Latin, sapphirus, means blue.

While sapphire has become the ultimate blue stone, it actually comes in virtually every color except red (red sapphires are rubies), including colorless and white, and such fancy colors as yellow, peach, orange, cognac, pink, violet, purple and green and all their many shades. In fact, white sapphire has become a popular natural diamond substitute for many people. Moreover fancy color sapphire often provides an alternative to other gems in similar colors that are less durable. It is considered the most important and versatile of the gem families.

Sapphire, sister to ruby, is known in the mineral world as corundum, which is a crystal structure composed of aluminum oxide. On the Mohs scale of hardness, sapphire ranks 9, the highest in the gem world after diamond. It is considered very durable, a great choice for rings and bracelets that are prone to knocks. Although sapphire is not as brilliant as diamond, it has striking luster.

Like ruby, sapphire may be found in a translucent variety that may display a six-rayed star effect when cut into a cabochon (dome) shape. This type is known as star sapphire, of which there are numerous synthetics on the market.

Natural gem-quality sapphire is found in many parts of the world, but the rarest gems are from Kashmir and Myanmar (Burma), most prized because their color is closest to pure spectral blue. Fine sapphire is also produced in Sri Lanka in limited supply, both in blue and fancy color. Sapphire is also found in Thailand, Cambodia, Tanzania, Madagascar, Australia and the United States (Montana).

Perfect natural gems--in color and appearance--are very rare and expensive. Controlled heating is commonly used in the trade to produce, intensify or lighten color and/or improve clarity in many gems including blue and fancy sapphire. This allows the trade to bring more, better quality gems to the market. Heat enhancement is permanent and stable. You can clean heated (and non-enhanced) sapphire with soapy water or commercial solvent and a brush. Mechanical cleaners are also safe, except for heavily included gems (filled with fissures).

Gemstone colors

Emerald - The greenest of the green, emeralds were cherished by the Romans above all other gems. Find out what makes this favorite of Cleopatra's so unique

Garnet - January's birthstone is famous for being as red as a ruby, but this colorful gem actually comes in every color but blue. Discover this elusive chameleon

Opal - Opals are the gem world's silvery mirrors, reflecting back every color in a flash of pastels or a streak of fire. Uncover this enchanting stone.

Peridot - Peridot is a gem that gets around. From ancient Egypt to present-day Apache mesas, even in space meteorites--you never know where its green gleam is going to show up.

Ruby - The color of courage and blood, rubies are even more precious per carat than diamonds. See why the Biblical authors to modern collectors use them as the measure of ultimate value.

Tanzanite- Millions of years in the making, deep-violet tanzanite revealed itself to humans only thirty years ago. Read about this newest discovery.

Sapphire - Blue as the perfect sky, sapphires have been used as protective talismans for centuries. Learn about the versatility of this stone that combines hardness and color variation like no other.

Tourmaline - Available in every color and saturation, this tough crystal has become a popular substitute for rubies, emeralds, and sapphires. Unmask this clever chameleon.

Turquoise - The lovely opaque blue of turquoise is produced by traces of copper in the stone. Elements of iron will also create a pretty, pronounced green hue. Oxides contribute to the stone's famous gray, brown or black veining.