The world gems have one prominent role. The rarer the stone is, the more valuable it is. The truth of gemstones is that they are formed due to peculiar mineral combinations and trace impurities. In other words, they are nature's marvels. They are beautiful for sure. But, they are adored because it took millions of years to form it. There might be more gemstones in the world than the human race has found. However, among what we have found, some gemstones are rarer than others. Here are 10 rarest gemstones in the world.
Red diamonds are probably the rarest of them all. There are less than 30 of them in the world. Its red colour doesn't come from the presence of any impurities but is the result of plastic deformation. Due to this phenomena, when the light is passing through the crystal structure of the stone, the light bends in a particular way that reflects a red colour. The intensity of the colour is different in some gemstones like pink diamonds. The largest red diamond in the world is called 5.11ct Moussaieff Red Diamond. Its worth was $8 million in 2011.
The title of the rarest gemstone in the world goes to purple diamond. Similar to the red ones, their colour is the result of crystal deformation. But, it requires huge amounts of hydrogen too for this phenomenon to occur. These two factors are hard to come by in exact same measures. Hence, purple diamonds aren't always formed in the same shade. Some of the popular hues are lilac, plum, orchid, and grape.
Purple diamonds that contain Boron are known as violets. They come with a shade of blue or grey. The most popular one in this lot is Argyle Violet which has a deep greyish bluish violet colour. When purple diamonds undergo a different anomaly during the formation stages, it may possess red and purple shades. A purple diamond named 'The Supreme Purple Star' appears to be deep purple from the top view and appears to be crimson cranberry purplish-red when tilted on its axis. The world gem market saw this wonder stone in London in 2002. Its origin and current location are a mystery.
Musgravite was first discovered in 1967 in Musgrave Ranges, Australia. It is an aluminium oxide with traces of magnesium, iron, and zinc. Musgravite is one of the hardest among rare gemstones with a hardness of 8.0-8.5 on Mohs scale. It was recently renamed by the International Mineralogical Association as Magnesiotaaffeite-6N’3S. It is a member of the taaffeite family of minerals and was renamed to clarify its complexity among other stones in the same family. Musgravite is found in light olive green, dark greenish blue, light to dark violet colours. They are always transparent.
Jeremejevite is a rare assemblage of aluminium borate mineral, fluoride, and hydroxide ions. It was first discovered in 1883 in Mt. Soktui in Siberia. The variety found in Russia is always tiny crystals, hence cannot be cut. Jeremejevite was named after the Russian mineralogist Pavel Vladimirovich Eremeev by French mineralogist Augustin Alexis Damour. It is mostly found in light blue to purplish blue colours. But, it can be colourless too. They are found in the Erongo Region in Namibia as well.
Fire Opal is a gemstone that is known for its wonderful structure. It is not a mineral but a mineraloid. It doesn't have the crystal structure that all minerals have. Opal is a hydrated form of silica or silicon dioxide. It can possess various colours as per the environmental conditions during its formation. They often have a transparent or translucent body that has orange or reddish colours. But, the structure of fire opal allows the diffraction of light because of which it shimmers with various colours.
Australia has 95% of the world's precious opal stones. However, they were discovered in the 19th century. Before the 19th century, opal stones were extremely rare and a favourite of European royalty. Opal stones are found in white and lemon colours too. But, black opal is the rarest. It has the same composition as fire opal. Lightning Ridge in New South Wales of Australia is the main source of black opal. These stones can be transparent, translucent or opaque due to circumstances it was formed under.
Serendibite was first discovered in 1902 in Sri Lanka, and it is extremely rare. It has a complex composition consisting of calcium, magnesium, aluminium, silicon, boron and oxygen. Its refractive index, twinning, and spectroscopic features make it different from sapphirine and zoisite. This gemstone is found in pale yellow, blueish green, and greyish blue colours. There aren’t many substances on earth that match the uniqueness of serendibite.
Poudretteite is another rare gemstone which was discovered in the 1960s in Mont St. Hilaire, Quebec, Canada. The gemstone was named after the Poudrette family who owned the quarry. It appears in pink colour and has Mohs hardness of 5. Even though it was discovered in the 1960s, first gem quality poudretteite was found in Mogok, Burma in 2000. The 9.41 carat stone is one of the largest poudretteite known to exist.
Alexandrite was discovered in the Ural Mountains of Russia in the 1830s. But, they are found in larger quantities in Brazil. Other places with Alexandrite deposits are India, Madagascar, Tanzania, and Sri Lanka. They appear in emerald green or ruby red colours as per the availability of light. It appears greenish in daylight as the human eye is more sensitive to green light. It appears reddish at night as the emission of green light is less at the time. The uniqueness of this gemstone comes from impurities such as iron, titanium, and chromium.
Grandidierite is almost exclusive to Madagascar. It was first discovered in 1902 by a French explorer Alfred Grandidier. It has bluish green colour which is transparent or translucent in nature. These rare gemstones are cut into cabochon most of the time. Faceted pieces only started appearing in the market after 2015.