Top Ten Rarest Gemstones
We all know diamonds are rare gemstones, but compared to the stones that are listed in this document diamonds are considered pretty common. Here are the ten rarest gems on earth.
Avg. $2000 USD/ Carat
Jeremejevite is a rare aluminum borate mineral with variable fluoride and hydroxide ions. It was first described in 1883 for an occurrence on Mt.Soktui, Nerschinsk district, Adun-Chilon Mountains, Siberia.
It occurs as a late hydrothermal phase in granite pegmatites in association with albite, tourmaline, quartz and rarely gypsum.
|Description:||Jeremejevite from Namibia occurs in well-formed, sharply crystallized, prismatic obelisk prisms with lustrous surfaces, sometimes two toned with a blue base and white terminations.|
|Mohs Scale:||6.5 - 7.5|
|Density(g/cm3):||3.28 – 3.31|
|Refractive index:||1.640 – 1.653|
|Colours:||clear, white, yellowish, greenish, blue, violet|
9. Black Opal
Avg. $2355 USD/Carat
These precious stones are highly prized and covetously sought after by kings, emperors, maharajas and sultans, the majestic opal has been desired throughout the ages. Yet many of these elites were denied the privilege of ever possessing the unique “Queen of Gems” known as the Lightning Ridge black opal.
Black opal is the rarest and most valuable of all opals and is generally found as a bar of various colours in a dark body of semi black and black crystal. Lightning Ridge of New South Wales is the worldwide home for black opal and is widely regarded as producing the best black opal in the world.
Black opal formed as nuggets are very rare to find. Even the colour base of black opals is different than it was years ago. The natural base is now more of a grey black colour rather than dark black as it used to be. It is quite difficult to find a Red Fire black opal.
History of Opal Use
Opal has been described as a cure for eye disease in the medieval times. It has been regarded as a symbol of hope, happiness and truth. Black Opal is regarded as an extremely lucky stone. High quality Black opal is more valuable than a diamond; up to $50,000 per carat. Opal is the October birthstone.
How Black Opal are Graded
Colour is the primary factor, but the graders also take into consideration the number of imperfections and faults, and whether the stone is the right shape to be cut into an oval or one of the other popular shapes.
8. Red Beryl Emerald
Avg. $10,000 USD/Carat
Red beryl is a very rare gemstone and has only been reported from a handful of locations. Prices for top quality natural red beryl can be as high as $10,000 per carat for faceted stones. Red beryl can be confused with pezzottaite, also known as raspberry beryl or “raspberyl”. Although, cut gems of the two varieties can be distinguished from their difference in refractive index.
Red Beryl also known as Red Emerald, is the rarest form of beryl (a mineral family which includes emerald, aquamarine, morganite, golden beryl and goshenite).
All the members of the beryl family are beryllium aluminum cyclosilicate (Be3Al2SiO3). Beryl is actually a colourless gem. The various colours are the result of the presence of trace amounts of impurities called chromophores. The chromophores found in Red Beryl are manganese ions (Mn3+) along with small amounts of iron, chromium, and calcium all leading to the gooseberry-red colour. The gooseberry-red colour is the result of these trace elements substituting for aluminum in beryl’s molecular structure.
The rough form of red beryl usually occurs as elongated hexagonal crystals. These hexagonal crystals are generally 2 – 10 mm long and 2 – 6 mm thick. Most are too small or too poor of a quality to be faceted. Red beryl crystals range in colour from orange-red to purplish-red with medium tones. The largest crystal ever found was 14 mm x 34 mm and weighed about 54 carats. To date the largest faceted red beryl weighed 4.5 carats.
Beryl has a refractive index of 1.564 - 1.574, a specific gravity of 2.66 – 2.70, and has a hardness of 7.5 to 8.0.
Many people consider Red beryl as the rarest gemstone on earth. Red beryl is estimated to be worth 1,000 times more than gold by weight. Red beryl is so rare that only one crystal is found for every 150,000 diamonds that are mined.
Avg. $35,000 USD/Carat
Musgravite is an extremely rare member of the taaffeite family. Musgravites were first discovered in 1967 in the Musgrave Range South of Australia. The first faceted Musgravite was not reported until 1993. The Musgravite weighed 5.93 carats with an oval cut from Tunduru, Tanzania. As of 2005 there were only eight musgravite specimens. Since then, the mineral has been found in Greenland, Madagascar, Antarctica, Sri Lanka, and Tanzania.
Musgravite's similarity to taaffeite has lead to some confusion. Some gemstones that were originally thought to be taaffeites, are actually musgravites.
The only known facet quality specimens are from Sri Lanka and Tanzania.
Musgravites are primarily sought as a collector gemstone.
|Refractive Index:||1.721 – 1.728|
|Mohs scale:||8 - 8.5|
|Colours:||Pale olive green, grey, mauve, grey purple|
Avg. $50,000 USD/Carat
Grandidierite is an extremely rare Mg-Al borosilicate, which usually occurs in aplites and pegmatites of metamorphic rocks and few plutonic rocks. Until now gemmy, facetable material, larger than a millimeter, is only found in Sri Lanka and Madagascar.
Grandidierite is named after the French naturalist and explorer, Alfred Grandidier (1836-1912), an authority on the natural history and geography of Madagascar.
|Refractive Index:||1.590 - 1.639|
|Density (g/cm3):||2.98 - 2.99|
|Colours:||Bluish green, greenish increasingly greener with greater Fe content.|
Grandidierite is an extremely rare mineral and gem with a beautiful blue-green colour. Although it is very rarely transparent, faceted, translucent gems have a beautiful colour.
Fe2+ and Fe3+ ions are the main chromatophores (colour giving elements) for the typical greenish-blue of grandidierite. It is trichroic, i.e. the colour varies from colourless to blue and green, depending on the view. The more Fe found in the crystal structure, the more intense bluish-green saturation. As usual, intensive coloured stones are more valuable than paler ones although high quality grandidierites are very expensive.
Avg. $50,000 - 60,000 USD/Carat
Painite is an extremely rare member of the borate mineral. It was discovered in the 1950s in Myanmar. It was named after the discoverer, Arthur C.D. Pain, who was a British mineralogist.
Painite has an orange-red to brownish-red colour similar to topaz due to trace amounts of iron. The crystals are naturally hexagonal in shape, and, until late 2004, only two had been cut into faceted gemstones.
|Refractive Index:||1.787 - 1.816|
|Density (g/cm3):||4.0 - 4.03|
|Colours:||Orange-red to brownish-red, violet , brown, red, orange|
The extreme rarity of painite began to change in 2001 with the discovery of a 55ct. crystal from the Mogok area. Since then, more than one thousand crystals of painite have been unearthed but only a small percentage were suitable for faceting. The painite from Nanya is very small with most crystals weighing less than 1 ct.
4. Blue Garnet
Avg. 1.5 Million USD/Carat
The rarest of garnets is the blue garnet. Blue garnet was discovered in the late 1990s in Bekily, Madagascar. It changes colour from blue-green in the daylight to purple in incandescent light, due to the fact of the relatively high amounts of vanadium (about 1 wt.% V2O3). Other varieties of colour-changing garnets exist. In daylight, their colour ranges from shades of green, beige, brown, gray, and blue, but in incandescent light, they appear a reddish or purplish/pink colour. Because of their colour changing quality, this kind of garnet is often mistaken for Alexandrite.
The crystal structure of this gemstone is nesosilicate meaning that regardless of the variety of garnet, they all tend to hold the same chemical composition formula: X3Y2(SiO4)3. As mentioned in the chemical composition formulas above, the X and Y elements of individual garnets change depending upon the variety of garnet being discussed. As with many aspects of the garnet, the hardness of the gem varies depending upon the individual chemical makeup of each variety of garnet.
Avg. 1.8 Million - 2 Million USD/Carat
Serendibite was first discovered in 1902 at Gangapitiya, near Ambakotte, Sri Lanka by G.T. Prior and A.K. Coomaraswamy. Prior to 2005, it was rare to find a facet-grade serendibite. There were only 3 known faceted serendibites, which originated from Sri Lanka. Due to the discovery of serendibite in Mogok, Myanmar, the availability of facet-grade serendibite drastically increased.
|Mohs scale:||6 – 7|
|Refractive Index:||1.701 – 1.706|
|Colour:||Blue, Blue green, Gray blue, Light yellow, Dark blue.|
2. Red Diamonds
Avg. 2-2.5 Million USD/Carat
Usually when people look for diamonds they look for diamonds that are colourless. Colouration in diamonds make it worth less. This is not the case in rare vibrant colour diamonds. One of the rarest fancy coloured diamonds are the red coloured diamonds. Red coloured diamonds are considered the rarest diamonds ever found. It is not known how many red diamonds there are in the world, but some think there are about 50.
Red diamonds are produced the same way as other diamonds but a special ingredient called nitrogen is added to the mix. Red diamonds are considered impure because of the nitrogen, but since the impurity causes it to be rare it becomes an extremely expensive. The Argyle mine in Australia produces a very small number of red diamonds and the best ones are auctioned off each year.
Today, there are two red diamonds that have been seen, both with a value of over 1 million dollars. They are the .95-carat Hancock diamond, and the 5.1 carat Moussaieff Red. Recently another 5.11 carat fetched an astounding 8 million dollars because of the intensity of the colour and the beauty of the ring itself.
Avg. 3 Million + USD/Carat
There are two types of jade, which are nephrite and jadeite. The traditional Chinese jade is called nephrite. There are large deposits of nephrite in China, but no jadeite. Jadeite was first imported into China from Burma in the 18th century.
Although there are many Jadeite deposits all over the world, the principal jadeite deposits are found in upper Burma (Myanmar). Type A jadeite is an untreated natural Burmese jadeite where the colour is 100% natural.
The rarest most valuable jadeite is called the imperial jade, coloured by traces of chromium. It has colour and transparency rivaling fine emeralds (slightly more yellow in tone than emerald).