If you study gemstone history, you realize that up until some years ago, gemstones had only two classifications: precious and semi precious. With advent of technology and awareness, and increased trade practices, we now have a comprehensive classification system of gemstones. All gemstones have the same origin: deep within earth. It is when they are available on the market after reasonable processing, that we come to their classification on the basis of where on earth they were found. In most instances, a difference in origin implies a subtle difference in color. For example, an expert can tell a Zambian emerald from a Colombian one, just by the difference in hue.
Most stones command a premium for their origin. This may be attributed to the fact that there are mines which have been producing for centuries, and there are newer deposits that are being found. Knowledgeable people usually look for established sources.
Amongst the most precious of gemstones available, sometimes the best emeralds can be even more valuable than diamonds. Emeralds are extracted from the mineral beryl which is not an uncommon mineral. Beryl interestingly is found in different colors which makes an array of beautiful beryl gemstones. Emerald is green variety of beryl ranging from intense green to a light green to a yellowish green. Though beryl is a common mineral, mines for fine emeralds are very rare making these gemstones rare.
In ancient times, emeralds were mined in Egypt, Austria and present-day Afghanistan. Later Colombia became one of the most popular sources of fine emeralds. These gems from Colombia are celebrated and prized for their shiny, vivid green color which is unadulterated by any blue tint. The famous Colombian mines Muzo and Chivor have been a popular source of emeralds since the pre-Columbian times, almost 5 centuries ago, when the Spanish explorers first arrived on the American continent. The rare Trapiche emeralds that have six rays emanating from the centre are also from Colombia. Today, emeralds from Colombia are easy to obtain. Their color is so prized that visible inclusions are accepted in these emeralds in return for the incomparable color.
A relatively new find in Zambia has made emeralds much more available on the market today. Zambian emeralds have captured a large portion of the market because they have a rich deep color and sometimes have very few inclusions. Zambian emeralds are a darker green than Colombian ones and some have a bluish tone. Rare specimens have a clear true green. Brazil also produces some fine emeralds that rival those of its famous neighbor. In fact, Brazil now produces more emeralds than any other country. Other known producers of emerald are Pakistan, Afghanistan, Madagascar, Nigeria, and Russia.
Emerald is one of the most difficult gemstones to cut because of the high value of the rough stone and many inclusions found in crystals. Emerald is most often cut in a rectangular step-cut, which is now known as the emerald cut. Smaller ones are found in rounds, ovals, pear shapes and marquise cuts.
Sapphires come from Sri Lanka, Thailand, Australia, and Cambodia. Nigeria, Kenya, Tanzania, China, Vietnam, Madagascar, and also the United States are some other sources. Montana in the United States produces a range of colors, mostly from deposits in the rivers; and deep blue sapphires from one of the largest deposits at Yogo Gulch. These sapphires from Yogo Gulch are small in size but make for a beautiful blue.
The most famous sources for sapphire are Kashmir and Myanmar (formerly known as Burma). The Kashmir sapphire was discovered in 1881 with a landslide in the Himalayas. This has a rich velvety color which is prized by connoisseurs. Burmese sapphires, from the same region that produces fabulous rubies, are also very fine. However, now these two sources account for a very small fraction of sapphire in the market.
Most of the fine sapphire available today comes from Sri Lanka, which produces a wide range of beautiful blues with rich saturated hues. Pink and violet sapphires from Sri Lanka are extremely vibrant in color and are generally rarer than blue sapphires.
Thailand (Kanchanaburi) and Cambodia are renowned for deep blue, even colored sapphires. Madagascar and Tanzania are the two more recent sources of sapphires.
Aquamarines are actually sisters to emeralds, since they belong to the mineral group beryl.
The coloring element to produce the beautiful blue green color is iron, which is substituted for aluminum in the crystal structure. The gem forms are found especially in geological formations known as pegmatites.
Aquamarine is found in Brazil, Zambia, Mozambique, Angola, Nigeria, Afghanistan and other countries, but chiefly Brazil is the major source. More recently Zambia, Mozambique and Nigeria have been producing some very fine quality stones. Some very dark blue aquamarine is mined in India. The largest high quality gem crystal ever discovered was a 200-kilogram crystal mined in Brazil. It was so clear that one could read a newspaper through it!
There are reports of aquamarine being mined in North and South Americas, as well as Russia and Madagascar.
The 'Santa Maria' class of aquamarines from Brazil is perhaps the most celebrated of aquamarines in the world. The Santa Maria gemstones have the rare, intense blue hue, which is the most prized color in an aquamarine. Similar nuances, ' Santa Maria Africana' aquamarines, are produced in Mozambique, Africa.
Ruby is the red cousin of sapphire, belonging to the same mineral: corundum. High quality rubies especially in larger sizes are extremely rare and command exorbitant prices. Sources for fine gem quality rubies are very rare making these exotic gems even more prized.
The best known source of fine rubies is Burma, now called Myanmar. The ruby mines of Myanmar are older than history. Rubies from the mines in Mogok often have a pure red color, which is often described as "pigeon's-blood". Myanmar also produces intense pinkish red rubies which are again vivid and extremely beautiful. Many of the rubies from Burma have a strong fluorescence when exposed to sunlight, which layers on extra color. Burmese rubies have a reputation of containing their vivid color under all lighting conditions. Demand for fine rubies is really limited by the tiny supply available; therefore new sources are always treated as exciting news. Burma ruby is now being outdone by Thai ruby, due to the new ruby rush in the area.
Most rubies are cut and marketed in Thailand, the world's most important ruby trading center. About 80 percent of world's ruby goes through Thailand at some point in the trading cycle. The largest ruby cutting factories are in the Kanchanaaburi area of Thailand. Bangkok is generally where the world's buyers come to purchase ruby.
A Masaai tribesman stumbled upon a shimmering blue crystal at the foothills of Tanzania's Mount Kilimanjaro in 1967. This stone was at first mistaken to be Sapphire but was later identified belonging to the family of mineral Zoisite.
Tanzanite is named after its country of origin and was conceived by Tiffany and co. From 1967 to 1972, an estimated two million carats of tanzanite were mined in Tanzania. The mines were later nationalized by the Tanzanian government.
In April 2005, a company called TanzaniteOne Ltd. announced that they had taken control of the portion of the tanzanite deposit known as "C-Block" (the main deposit is divided into five blocks). In August 2005 the largest tanzanite crystal was found in the C-Block mine. TanzaniteOne, through its no-profit subsidiary, The Tanzanite Foundation, has introduced its own color grading system. The new system's color-grading scales divide tanzanite colors into a range of hues, between blue violet and violet blue.
The most relevant fact about tanzanite is that firstly, it is found in only one place in the world. Secondly, the supply is likely to exhaust itself by the next two decades. Makes it an heirloom, truly.
Dark blue and yellow sapphires come from Australia, but are so scarce that very few are available in the world marketplace. The Australian gemstones are dark inky in appearance.