10. Musgravite -
Musgravite was discovered in the Musgrave region of southern Australia in 1967. Its color is anywhere from greenish grey to purple and it is in the same family with Taaffeite, another gemstone on this list. When musgravite was first found, there were only 8 gem-quality stones. Today, however, it has been found in Tanzania, Madagascar, Antarctica, Greenland, and Sri Lanka. Its value is set at approximately $35,000 per carat.
9. Jadeite -
Jadeite is an olive to emerald green stone found in Myanmar. Coloring of this stone varies and the most valuable specimens have a translucent green hue, although it can also be yellow, lavender, grey, or orange. This is one of the two forms of pure jade and the most expensive. Jadeite is an extremely durable stone and in ancient times was used to make weapons and tools, particularly in the Mayan and Aztec cultures. It was also thought to cure pain. Some specimens have been discovered in Guatemala, US, Canada, and Russia. This gemstone has been used in necklaces and has an average market value of $20,000 per carat.
8. Alexandrite -
Alexandrite is interesting in appearance due to its color-changing characteristics. Depending on the cut of the stone and the lighting it is presented in, alexandrite can change from reddish purple hues to greenish blue. Discovered in the Ural mountains of Russia in 1830, gemologists once thought the supply had nearly run out. It was later found in East Africa, Sri Lanka, and Brazil. Alexandrite is formed when beryllium and chromium are present in the same location, the same elements necessary for the more common emerald gemstone. This stone is set in a variety of jewelry and can sell for $12,000 per carat. Many of the alexandrite jewelry today is synthetic, made instead of corundum and vanadium.
7. Red Beryl -
The red beryl gemstone is commercially mined in the Wah Wah mountains of Utah, a state in the US. This stone, 1,000 times more valuable than gold, has only been found in Utah and New Mexico (jewelry quality stones have only come from Utah). The Utah Geological Survey estimates that for every 150,000 gem quality diamonds, 1 red beryl crystal will be found. The largest crystal found at the mining location was 2 centimeters in width and 5 centimeters long. Typically, the highest quality stones are under 1 centimeter in length. Some people have incorrectly referred to this stone as a “red emerald”. When cut and polished, the red beryl can sell for between $2,000 and $10,000 per carat.
6. Grandidierite -
Discovered in 1902, in the southern region of Madagascar, grandidierite is an extremely rare gemstone. A few stones have been found in Sri Lanka, Namibia, and Malawi, but they were not of jewelry quality. The stone is bluish green in color, with the more transparent hue looking almost like the tropical ocean. The more opaque the coloring, the less valuable the stone. It is a relatively hard stone, although, a ring setting might be prone to scratches. Due to its wide variation in coloring, pricing for this stone is also quite variable. Specimens can be purchased for anywhere from $1,000 to $3,000 per carat.
5. Benitoite -
Coming from the San Benito river in the US state of California, is the benitoite gemstone. This rare stone was discovered in 1907 and is characterized by its deep bluish purple color. Interestingly, it glows under UV light. Some stones have been found in Japan and the state of Arkansas, but the only mine is located in its place of origin. Collectors seek out the benitoite; stones over 1 carat are, however, extremely rare. The state gemstone of California, the benitoite is often set in jewelry and can be purchased for between $3,000 and $4,000 per carat.
4. Black Opal -
Opals are typically white, milky, or bluish in color. The black opal, however, takes on a beautiful greyish to black hue with specks of iridescent, multicolored “fire” sparkling inside. This coloring is caused by the presence of carbon and iron oxide. The darker the tone, without being completely opaque, the more valuable the stone. These gemstones are very soft, making them best for earring settings that might not be exposed to harsh conditions. Mining for the black opal occurs nearly exclusively at the Lightning Ridge Mine in New South Wales. In 2008, the black opal became the national gemstone of the country. Due to its rare nature, the black opal is normally priced a little over $2,300 per carat.
3. Tanzanite -
Tanzanite originates from one very specific location, the foothills of Mt. Kilimanjaro in Tanzania. This gemstone was not discovered until the 1960’s, making it relatively new to the jewelry market. Tiffany and Company promoted this rare stone until it became the second most popular blue gemstone (after the blue sapphire). This stone has a bluish purple color that varies in intensity, sometime light blue and other times very dark purple. The more vivid the color, the more expensive the stone. This blue color is because of the presence of vanadium, which becomes darker after being heated for 30 minutes. Most tanzanites on the market have received some heat treatment. Due to its scarce occurrence, estimates suggest that tanzanite mines will be depleted over the next 20 to 30 years. This gemstone can be purchased between $600 and $1,000 per carat.
2. Taaffeite -
Ranging from nearly colorless to increasing shades of violet, the taaffeite was discovered in 1945. Its name comes from its discoverer, Richard Taaffe. The first taaffeite was not discovered while digging or mining like the majority of other gemstones. Instead, it was already a cut and polished stone that had previously been mistaken for a spinel. Currently, only a few of these stones are in possession and they have only ever been found in Sri Lanka and Tanzania. The only use for this gemstone is in jewelry although it is so rare that taaffeite jewelry is not readily available on the market. Until more deposits are discovered, they will continue to be worth anywhere from $1,500 to $2,500 per carat.
1. Red Diamond -
Diamonds occur in a wide range of colors including: yellow, blue, white, pink, red, and black. The rarest of these, is the red diamond. Found mainly in Brazil, Africa, and Australia, less than 50 true red diamonds are believed to exist. These true stones each weigh less than a half carat. Other colored diamonds are created due to an impurity, but not, however the red diamond. This gemstone gets its color from an atomic deformation in its structure. Natural red diamonds are usually priced at more than $100,000 for anything over .2 carats.