This is not a hard and fast rule about establishing an opinion about the rarest gemstones and rocks in the world. However, a collective opinion can be made about selecting the world rarest rocks and minerals in the world. Here are a few of them:
10. Poudretteite
In the 1960s, Poudretteite was discovered in the 
Poudrette quarry of Mon Saint Hilaire, Quebec.
9. Benitoite
Benitoite is found near the San Benito River in California. 
This is a blue to the purple gemstone. It was first discovered in 1907. Its colour looks chalky under UV Light.
8. Tanzanite
Tanzanite is only found near the foot of Mount 
Kilimanjaro in Tanzania. This is a lovely blue variety of zoisite. until the 1960s, it was not discovered commercially. Tiffany & Co. Heat became the cause of its popularity.
7. Grandidierite
Grandidierite is also the world rarest rocks and mineral. The formula of grandidierite is ((Mg,Fe2+)Al3(BO3)(SiO4)O2). It was first discovered in Madagascar in 1902. It is a bluish green gemstone. A gem quality is hardly found.
6. Jeremejevite
Jeremejevite is also one of the rarest gemstone and mineral. 
First, it was found in Siberia at the end of the 19th century. This mineral has aluminum and borate minerals. It has variable fluoride and hydroxide ions. It is almost $2,000 per carat. The colour of jeremejevite s from sky blue and pale yellow. The best quality is found in Namibia.
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5. Painite
Red coloured Painite is usually based on hexagonal-shaped. 
It was considered the rarest on the planet. In 1950, it was first discovered in Myanmar by the British gemologist Arthur CD Pain. The stone name was put on this gemologist. It is only found in Myanmmar and hardly found in any other location.
4. Black Opal
Opals usual colour is white with rainbow-colored inclusions. 
However, in opal variety, black opals are the rarest rock and mineral of the world. They are found in mines in the Lightning Ridge area of New South Wales in Australia. This has also value in the market. The world valuable and expensive black opals is the "Aurora Australis,". It was discovered in Lightning Ridge in 1938. Its value was AUS $1,000,000, or about $763,000 U.S. Its weight was 180 carats.
3.Red Beryl
Red Beryl is called red emerald or bixbite also. It is found in is found in Utah and Mexico. This is also one of rarest gems and mineral. It is formed by beryllium, aluminum, silicon and oxygen.
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2. Alexandrite
The Alexandrite is also one off top rare mineral on the earth.
It has colour changing effects. Its scarcity is relative to diamond. What is unique in this gem, it includes titanium, iron, and chromium elements.
1.Padparadscha Sapphire
Padparadscaha is pronounced pad-pah-raj-ah). Padparadscaha is a pink variety of sapphires. They are extremely rare. They are found in Sri Lanka as well as parts of Madagascar and Tanzania. It has a beautiful colour combination of pink and orange hues. The unique combination of pink and orange hues make this stone one of the most sought after by collectors. The average value of the gem is $8,000 for high-quality gems.
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