The Most Widely Traded Gemstones



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)

Ruby is probably the most well-known colored stone. The Hindus call ruby "The Lord Of Gems". Chromium creates the beautiful red in ruby. The supply of these gems is severely restricted due to the political instability of the source countries in Southeast Asia. Further, mining methods in these areas are so primitive that pouring water on a hillside or sifting gravel in a stream represent state-of-the-art extraction. The main sources of ruby are Burma, Thailand, and recently Madagascar. The problem with Burma production in the "Golden Triangle", is that the region is extremely volatile. Ethnic tribes, such as the Shans and the Karens, have been fighting the Burmese Central Government since 1949. Also, Mogok production has been declining for decades and prices are often higher in Burma than in the United States. The rarest rubies are mined in Mogok, Burma. In 1992, a new mine was discovered at Mong Hsu (pronounced Mine Shu). The problem with Mong Hsu ruby is 99% of the material is heated/fracture filled. Most rubies sold today in jewelry stores are treated Madagascar stones. They tend to be too dark or too light compared to Burma gemstones. They sell for 50%-75% discount to Burma stones. Most collectors specialize in unheated Mogok Burma ruby.




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)

Many large red gems in royal vaults turned out to be spinels, not rubies as previously believed. As a matter of fact, the Black Prince Ruby and the Timur Ruby in the British State Crown Jewels, are actually spinels. Today, the finest spinels are found in the Mogok area of Burma before being smuggled out of Asia. There is some new East African and Vietnamese spinel, however, we do not recommend collecting these stones, except the finest specimens, because their colors tend not to be gem red. Fine spinels are at least 200 times rarer than rubies, possess more "fire" (dispersion), and are available for 25% of the per carat price of Thai rubies. Spinel is not altered by heat or irradiation. The amount of fine spinel in today's market is severely limited. National Gemstone recommends gem reds, hot pinks, and flame oranges. Occasionally, NGC finds an amethyst, blue, or color change (blue to purple) spinel.




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)

Most people tend to think of sapphires as being only blue. Actually, sapphires are discovered in a wide array of colors. The most sought-after fancy color is the padparadscha, which means "lotus flower". It is orangey-pink-salmon. The second most desirable color is electric pink. These stones are extremely vibrant and are often mistaken for, or sold incorrectly as, Burma ruby. Many speculators buy and sell violet, orange, golden, white and yellow sapphires. They feel that once these gems receive more exposure, they will become a favorite among connoisseurs. The main source of fancy colored sapphires is Southeast Asia.




Mandarin Orange Garnet (Hardness: 7.0)

In 1993, a new variety of spessartine garnet was discovered in Namibia, Africa. Mining is accomplished in a remote desert location under extremely difficult conditions. Most of the production is below one carat, although larger gems are occasionally found. Mandarins should possess a vibrant, electric orange color and be eye clean. This gem is one of the hottest new collector gemstones on the market. These gems are not heated, oiled, or treated in any way.




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.



Collector Gems

Other gems NGC trades in include: alexandrite, cat's-eye chrysoberyl, Burma star ruby, Burma star sapphire, demantoid garnet, color-change garnets and red beryls. Call NGC or see How To Collect Gems for Fun and Profit and The Gemstone Forecaster for more specific information on these gems.