Diamonds - White And Colored (Hardness: 10)

Originally derived from the Greek, "adamas", the name implies extreme hardness. Although diamonds are only carbon, they are the hardest substance mankind has ever discovered. Historically, diamonds have been purchased as symbols of love and trust; today many individuals utilize them as the ultimate form of concentrated wealth.

National Gemstone specializes in colored diamonds. These diamonds are extremely rare; it is estimated there are no more than 4000 carats of colored diamonds for sale at any given time vs. multi-millions of carats of white diamonds. Therefore, these diamonds are less susceptible to downward price movements. These richly hued diamonds, called fancies, are available from NGC in blue, pink, green, orange, yellow and champagne. Fancy diamonds are the ultimate connoisseur gemstones.

Emerald (Hardness: 7.5)

Since 2500 B. C., emerald was mined in Upper Egypt. The Cleopatra mines were "lost" for a millennium, only to be rediscovered in 1818 by a French scientist. In the early 13th century, Chibcha Indians mined emeralds in what is now known as Colombia. Other Indian cultures such as the Incas, Toltecs, Aztecs, and Mayans sent emissaries to barter for emerald. Early in the 16th century, the Spanish Conquistadors invaded South America searching for wealth. Although the Indians offered their emeralds and gold jewelry as gifts to the Spanish, they were tortured to reveal the source of the gems. The Indians never told the Spanish. According to historians, a Spanish settler rode into Muzo, Colombia with a horse that was lame. Upon checking the animal, he found an emerald embedded in its hoof. Everyone in the village retraced the animal's trail and discovered the now famous Muzo Mine.

Over the years, many corporations, government agencies, and individuals have sporadically worked the mines. Each attempt has had its share of corruption, thievery, and killings. Colombians refer to it as "emerald fever". In 1972, as the result of 900 deaths in the region, the Colombian government closed down the mines. Today, the emerald mines are leased to private businessmen. However, as long as "green fire" can be mined, murder and general depravity will surely be linked to the production of emerald.

The most prized emeralds are mined in Colombia, South America. Recently, new deposits of emeralds have been found in Zambia and Zimbabwe in East Africa. However, they are not as accepted as the Colombian gems, and tend to sell for a 50% discount to the Colombian gems.

Ruby (Hardness: 9)

Sapphire (Hardness:9)

Both ruby and sapphire belong to the same gemological family, corundum. However, titanium creates the blue in sapphire. The leading sources of blue sapphire are Australia, Madagascar, Thailand, Sri Lanka (Ceylon), Burma and the Kashmir mines in India. Kashmir sapphires are considered the ultimate sapphire. They are rich, velvety, and serenely soft. Originally discovered in 1882, the stones were so plentiful the locals would use them as flint stones. By 1925, the mines were nearly depleted.

Burma sapphires are also extremely desirable. However, Burma sapphire possesses the same supply problems as does Burma ruby, since the two are mined together. Burma sapphires are a rich electric blue color. Sri Lankan sapphires are relatively affordable, with the exception of a few fine stones. Stick with the top colors, or purchase gems that are not heated.

Spinel (Hardness: 8)

Tsavorite (Hardness: 7.5)

This beautiful green garnet was discovered in 1968 in the Tsavo National Game Park in Kenya. When discovered, miners thought they had discovered a new source for demantoid garnet. Demantoid is the only other green garnet (once mined in Russia) and now trades from $10,000 per carat and up. Many experts believe tsavorite will be the next demantoid, extinct and ultra-rare. Many tsavorite aficionados believe if tsavorite had been discovered before emerald, emerald would be called tsavorite, and tsavorite called emerald.

High quality tsavorite is 200 times rarer than emerald, is cleaner, more brilliant, is not altered with with oil or heat. Plus, tsavorite is available for 1/4 of the price of emerald. Today there are small mines operating in Kenya and Tanzania. Any stone above three carats is considered large. Sporadic production probably means higher prices.

Fancy Sapphire (Hardness: 9)

Mandarin Orange Garnet (Hardness: 7.0)

Paraiba (Hardness: 7-7.5)

Brazil's Paraiba neon tourmaline hit the market at the Tucson Gem Show in 1990. No one had ever seen such windex blue, electric green, and Caribbean sea green colors before in a tourmaline.

Many suspected the material was irradiated and dealers and collectors were cautious. After the major labs decided the material was heated, but not irradiated, the goods took off. Neon fluorescent blue Paraiba gemstones, which were $1000 per carat in the 1990, today one carats can trade for over $40,000 per carat. Pure greens are slightly less expensive.

Other Paraiba-like stones were discovered in Nigeria in 2003 and in Mozambique around 2006. The high price of these stones is justified because nothing quite compares to these electric colors in nature. Their long term and ongoing price appreciation mimics the rise of the colored diamond market. Like Kashmir sapphire, the Brazilian and Nigerian material can only be repurchased from old collectors.