World’s Rarest Gemstones

The French essayist Jean de la Brueyere wrote that the rarest things in the world, next to a spirit of discernment, are diamonds and pearls.

While diamonds are certainly rare, natural colored diamonds are even harder to come by. The rarest of all is the red diamond, with fewer than three dozen ever found, most at less than half a carat. Red diamonds are generally not available at any price, but they occasionally appear at auction, where they have sold for more than a $1 million per carat. The most famous and largest red diamond is the trillion-cut Moussaieff (also called the Red Shield), which is a whopping 5.11 carats.

Though the Red Shield is considered the single most concentrated source of wealth, the Heart of Eternity, a 27-carat blue diamond valued at $16 million, is deemed the most expensive colored diamond in existence. The blue garnet is another rare and costly gem; it is especially noteworthy because it changes color from blue-green in daylight to purple in UV light.

California is home to benitoite, which is found only in San Benito County. This stone, which when available sells for a relatively affordable $2,000 a carat, is a deep blue and disperses light much like a diamond. In 1985, benotoite was named the state gemstone of California. If you can find the ultra-rare taaffeite, a purple-to-red stone which boasts a double refraction and is literally a million times more scarce than diamonds, it’s comparatively affordable at $500 to $4,000 per carat.

The Guinness Book of World Records once called painite, discovered in Myanmar, the rarest gem on earth. From 1956 until 1979, only three crystals of this hexagonal mineral were known to exist! This mineral reveals different colors from different angles, and while it can show reds or pinks, orange and brown shades predominate. Despite new discoveries of painite, complete crystals remain few in number and facet-quality material remains even rarer.