Tanzanites, which are a vivid blue in colour, were discovered in 1967 in the foothills of Mount Kilimanjaro and are a thousand times rarer than diamonds.
With the current supply of tanzanite being 'controlled' by the mine owners, prices are expected to continue to increase over time. In fact, many projections indicate that some day tanzanite could be the most expensive gemstone on earth.
The opportunity exists today to purchase tanzanite relatively inexpensively; around 600 to 700 per carat. When compared to the prices of fine rubies, sapphires and alexandrite which sometimes sell for 1000's per carat.
The supply of Tanzanite is limited to a 5km strip of land near the mountain and prices can be volatile. But given how few tanzanites there are around, they make an excellent investment.
The best and safest way to invest in gems is to buy vintage jewellery, the average price of which has risen by about 4% a year in the past 18 years, according to London based Art Market Research. In the past, jewellery was bought mainly for its gem content, and that would appear to still be the case. With vintage jewellery, you can usually be pretty sure that a gem has not been treated and you should also end up paying a fair price for it. There is, for example, a 1.92 carat coloured diamond Tiffany ring about to come up for auction at Bonhams London.The estimate for this particular piece is £8,000-£10,000. A similar ring, with only a 1 carat stone, would cost you £24,000 if bought new. However, investors are looking just as much for design and craftsmanship, so the Tiffany name will add to the stone value.
One hundred years ago, the craftsmans time was not as valuable as it is now and jewellers would spend a great deal longer working on each piece than is generally the case today. The provenance of jewels from master jewel houses, such as Boucheron, Chaumet, Cartier, Van Cleef & Arpels and, of course, Fabergé, greatly increases the value of the piece.
All the major auction houses, including Bonhams, Sothebys and Christies, have regular auctions of gemstones and jewellery. All have experts who will talk you through the pieces in the auction, allow you to view them and be able to provide you with detailed information. Buying this way also has the added benefit of the assurance that each piece has been authenticated by experts. The viewing and the bidding takes time and effort, but it should be worth it.