Composition: Calcium, Aluminum, Silicon, Hydrogen, Oxygen
Market Value: $600-$1,000 per carat.
This blue-purple stone is another color-shifting gem. It is found only in the foothills of Mount Kilimanjaro, in Northern Tanzania. It may be mined out within 20-30 years due to the limited availability, It will of course become even more valuable and desirable.
Composition: Magnesium, Beryllium, Aluminum, Oxygen
Market Value: $1500-$2500 per carat
Found in range of hues ranging from nearly colorless to lavender, mauve and violet, Taaffeite occurs in Sri Lanka and Tanzania. Other sources may be discovered. Named for Australian gemologist Richard Taaffe, who discovered a cut and polished specimen of the stone in 1945, Taaffeite are very rare in fact only a handful of these precious stones have ever been found, thats why they are a true collector's gem.
Composition: Silicon, Hydrogen, Oxygen
Market Value: $2,355 per carat.
Black Opal is the most valuable gem of its kind. It is the rarest type of Opal and the national gemstone of Australia. Black Opal comes from the Lightning Ridge mine in New South Wales.
Composition: Barium, Titanium, Silicon, Oxygen
Market Value: $3000-$4000 per carat.
Benitoite is the Official state gem of California and a coveted collectors' gem. Benitoite also sold in jewelry, though rarely available in sizes of one carat or more.It is found near the San Benito River in California, Benitoite is a blue to purple gemstone first discovered in 1907. Under UV lights, it glows a brilliant chalky blue. A few specimens have been found in Arkansas and Japan, but the only commercial mine is in San Benito County, California.
Red Beryl (Bixbite)
Composition: Beryllium, Aluminum, Silicon, Oxygen
Market Value: $10,000 per carat.
Red Beryl has been described as 1,000 times more valuable than gold. Red Beryl has only been found in Utah and New Mexico and the only commercial mine is found in the Wah Wah Mountains of Utah.
Composition: Beryllium, Aluminum, Oxygen
Market Value: $12,000 per carat.
Alexandrite is a color-changing gemstone: its hue shifts from red to green depending on the light it's exposed to.This rare gemstone was thought to be mined out after the original deposits, found in 1830 in Russia's Ural Mountains, were nearly exhausted. Recent finds in Brazil, East Africa and Sri Lanka have brought this stone back on the market, but it is still one of the world's most coveted stones. It is named for Tsar Alexander II of Russia.
Composition: Sodium, Aluminum, Iron, Silicon, Oxygen
Market Value: $20,000 per carat.
Jadeite may sound like the various semi-precious stones known informally as "jade," but this incredibly rare gem is many times more valuable. Jadeite is mainly found in limited quantities in Myanmar.Prized most when it is colored a deep, translucent green
Composition: Magnesium, Beryllium, Aluminum, Zinc, Iron, Oxygen
Market Value: $35,000 per carat.
Musgravite is in the same family as Taaffeite, Musgravite was discovered in 1967 in the Musgrave Range of Southern Australia, and for many years there were only eight known specimens. This stone's color ranges from a brilliant greenish gray to purple. Recently, small quantities of Musgravite have been located in Greenland, Antarctica, Sri Lanka, Madagascar and Tanzania.
Composition: Calcium, Zirconium, Boron, Aluminum, Oxygen
Market Value: $50,000-$60,000 per carat.
In the 1950s, minerologist Arthur C.D. Paine encountered an unusual brownish stone in Myanmar that turned out to be one of the planet's rarest gems. For decades, only two cut specimens were known to exist, causing the jewel to be more or less "priceless."
In recent years, a few more crystals have been found.
Market Value: $83,187,381, or about $1,395,761 per carat
This Fancy-Vivid-Pink diamond was mined in 1999 in South Africa. Weighing in at 59.6 carats, this gem was sold by Sotheby's for a record $83 million which is more than any other diamond or any gem ever sold.