Which Gemstone Is The Rarest In The World ?

Tanzanite is one of the best-selling colored stones in today's gem and jewelry markets. ... At the same time, tanzanite is a rare gem. All of the known deposits are confined to a few square miles of land in northern Tanzania. It is the only gemstone with a large and growing popularity that has such a limited known supply.                                                   

Tanzanite is the blue and violet variety of the mineral zoisite belonging to the epidote group. Like the rare gem alexandrite, tanzanite also has the ability to color change from more blue in daylight to more violet in incandescent light. It's been said that Tanzanite is like Diamond, but Tanzanite is at least 1000x more valuable and more rare than Diamonds. Diamonds have been minded in large quantities. You can't say that about Tanzanite. Other gemstones, like  Ruby, Sapphire or Emerald... have been minded for 1,000s of years...Tanzanite minded only about 25 years.  Tanzanite was discovered by Manuel de Souza in the Mererani Hills of Manyara Region in Northern Tanzania in 1967, near the city of Arusha and Mount Kilimanjaro. Significant tectonic plate activity and intense heat formed Mount Kilimanjaro, and in this process, the Mozambique Orogenic Belt (one of the most mineral-rich places on Earth), was formed as well. It is believed that it was during this process that rough tanzanite was formed.

Tanzanite is the birthstone for the month of December. The price varies depending on color and size.  For richly colored AAA Tanzanite, 1 ct is approximately worth $300-$425 per carat. 2ct sizes reach $450-$650 per carat. 3 carats and up will reach $650-$750 per carat.On mohs scale it is from 6 to 6.5 of hardness. Tanzanite is safely used in fine jewelry including pendants, earrings and with some caution rings and bracelets.