COLORED GEMSTONES

Fine ruby is the rarest of all colored gems, and Burmese (Myanmar) ruby has long been the premier investment gem. Fine unheated Burmese rubies in larger sizes draw prices as high as $300,000 to $400,000 a carat at auction. Vivid red — a color known in the trade as pigeon’s blood — is the most valuable color. Rubies tend to have inclusions, so color is more important than perfect clarity.

Burma rubies are by far the most valuable, but fine unheated rubies from other locations — Madagascar, Mozambique and Tanzania — are rapidly increasing in value.

Based on sales from the top auction houses, blue sapphire is the second most popular colored stone for investment.

The rarest sapphires are from Kashmir, but no new material has been mined there in more than 100 years. The next most valuable is Burma (Myanmar) sapphire, followed by Ceylon (Sri Lanka) and Madagascar. Fancy color sapphires — yellow, pink and padparadscha — are now popular with investors as well.

Colombian and Brazilian emeralds, especially in large sizes and quality, are highly valuable. Zambia is another known source of desirable emeralds. The fracture-filling of emeralds is a normal treatment for the majority of emeralds and this is a very common, accepted practice, even in highly valuable stones. Quality emeralds are also being sourced in many other locales, including the United States. The most desirable emerald colors are bluish green to pure green, with vivid color saturation and tone that’s not too dark, with good transparency and even color distribution.

Spinel is a relative newcomer as an investment gem, but some of (what was originally thought to be) the most famous rubies in the world, such as the “Black Prince’s Ruby” on the Imperial State Crown of the United Kingdom, are actually spinels.

The most valuable spinel colors are red, hot pink, and flame orange. Red Burmese spinels and the neon pink-red spinels from Mahenge, Tanzania have the best investment potential. Spinel is completely untreated and prices on fine pieces have risen significantly in the last 5 years.

Tsavorite Garnet is a rare gem from East Africa that has begun to challenge emerald as the finest of the green gemstones. Unlike emerald, tsavorite is always untreated, and has the potential to be more brilliant due to its higher refractive index.

Tsavorite over 2 carats are very rare, and fine stones over 4 carats count as exceptionally rare. The optimal tzavorite has a range of 5-6 for both tone and saturation, as per the GIA Color Grading System.

Spessartine Garnet is a bright orange garnet colored by manganese. The finest examples, often referred to as Mandarin Garnet in the trade, are a pure orange that is one of the most vivid colors in the gemstone world.

The pure orange specimens are very rare, and come mainly from Africa, particularly Nigeria and Namibia. Large clean stones are quite valuable and display remarkable brilliance.

Alexandrite is a rare chrysoberyl that is popular with collectors for its striking color change and excellent hardness (8.5 on the Mohs
scale).

Alexandrite was first discovered in Russia and Russian specimens are very rare and valuable. Today, the highest quality alexandrite comes from Brazil, with medium grade material from Tanzania.

Fine translucent emerald-green jadeite is known as Imperial Jade. This rare gem is found only in Burma (Myanmar) and is coveted by collectors around the world, especially in Asia.

Type A jadeite is untreated, natural Burmese jadeite where the color is 100% natural.

Only jadeite of these qualities are deemed worthy of investment.

The Ouro Prêto area in Minas Gerais is the source of the rarest topaz known as imperial topaz. This topaz is golden-orange to orange to pink, pinkish-red or violet in color.

The color should be completely natural, with no enhancement by heat or other methods. Stones with a hint of pink or red are the most valuable, with a pure red natural topaz counting as extraordinary.

Paraiba tourmaline is a rare copper-bearing variety of tourmaline with a distinctive neon-like glow. It was first discovered in the Brazilian state of Paraiba in 1989. Since then, small deposits have been found in Nigeria and Mozambique

The Brazilian paraiba is still the most valuable, but color and clarity are more important than origin for these rare gems. Clean paraiba tourmalines with exceptionally vivid color are the most valuable.