Tanzanite, discovered only fifty years ago in the foothills of Mount Kilimanjaro, is a relatively new entry to the list of desirable gemstones. Given its short history compared to more familiar gemstones like emeralds and diamonds, it’s not unusual to encounter some confusion about what factors contribute to the value of an individual tanzanite.
While many of the categories that determine the value of other stones—cut, clarity, and carats—also apply to tanzanite, it’s important to know that color is the most important thing to consider with this rare gemstone. The finest tanzanite not only displays an intense blue or blue-violet color, but it is also pleochroic, meaning that it displays flashes of different colors depending on which direction it is viewed from. In fact, its unusual and beautiful color is what has propelled its unparalleled rise in popularity since its discovery. The most valuable tanzanite has a deeply saturated color; while paler stones are also attractive, they do not command the same price as more vividly colored gems.
Tanzanite is cut into a variety of shapes for jewelry. The primary consideration in determining a good cut is showing the stone’s color and pleochroic properties, which means the cutter must properly determine the direction of crystal growth to achieve the best effect. A secondary consideration is the overall size of the stone. The cutter will generally try to achieve the largest possible cut stone from the raw material, unless this will result in significantly inferior color. A well-cut tanzanite will be brilliant and symmetrical, no matter what the shape chosen.
Because of the geological processes that form this stone, tanzanite can readily be found without inclusions visible to the naked eye. As with other gemstones, tanzanites with fewer inclusions are more valuable, and those that do have inclusions that can be seen without the aid of a jeweler’s loupe sell at a significantly lower price.
As with other gems, when all other factors are equal, a large tanzanite will cost more per carat than a small one. However, the most intense colors tend to be seen in sizes of five carats or more; stones of one to two carats tend to be much lighter in color than larger stones. In large sizes, the best-quality tanzanite can sell for $700 per carat or more. While tanzanites are available in a variety of sizes, gem-quality stones over thirty carats are quite rare.
One final factor to take into consideration is tanzanite’s rarity. The entire world’s supply of tanzanite comes from a single location only one and half miles square. While experts may disagree on exactly when the mines will run out, they agree that it will happen. Therefore, prices can only be expected to rise.
You may believe that a high-quality tanzanite is beyond your reach, since it is so rare and valuable. However, you can still find excellent deals on large, dark-blues tanzanite by shopping at auction. The live online auction at Auction King regularly features beautiful tanzanite necklaces, rings, bracelets and earrings for a fraction of their retail price. Sign up for a free online account today and get this rare gemstone before it’s gone for good.