Grandidierite is a rare mineral originally discovered in southern Madagascar in 1902. Unlike spinel, taaffeite displays the double refraction property which allows distinguishing between these two minerals. Anderson et al., classified taaffeite as a spinel-to-chrysoberyl intermediate mineral. The confusion between spinel and taaffeite is understandable, as certain structural characteristics in both are identical. It was only known in a few samples for many years after, and it is still one of the world’s rarest gemstone minerals.Ĭhemical and X-ray analysis confirmed taaffeite ‘s main constituents as beryllium, magnesium and aluminum in 1951, making taaffeite the first mineral to contain both beryllium and magnesium as essential components. Most of the gem pieces had been misidentified as spinel, prior to Taaffe.

As such, this is the only gemstone that was first identified from a faceted stone. Taaffeite BeMgAl4O8 is a mineral named after its discoverer Richard Taaffe (1898–1967) who found the first sample, a cut and polished gem, in Dublin, Ireland, in October 1945. That made it the most expensive emerald per carat ever sold. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor.Īt the Christie’s auction, it was purchased for $5.5 million, or $305,000 per carat.

Beryl has a hardness of 7.5–8 on the Mohs scale. Emerald – $305,000 per carat EmeraldĮmerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium. It is like pink diamonds, are highly debated as to the source of their color, but the gemological community most frequently attributes both colors to gliding atoms in the structure of the diamond as it undergoes tremendous pressure during its formation. They are commonly known as the world’s most expensive and rare color of diamonds, more so than pink diamonds or blue diamonds. Red Diamond is a diamond with the same mineral properties as colorless diamonds, displaying red color. Red Diamond – $1,000,000 per carat Very rare Argyle Cardinal Fancy Red diamond Known as the “Pink Star” diamond, it’s the largest Fancy Vivid Pink diamond ever graded as Internally Flawless by the Gemological Institute of America. In 2017, a stunning pink diamond weighing 59.60-carats was sold at a Sotheby’s auction in Hong Kong for a record-breaking $71.2 million. The Pink Star is the only pink diamond in the world that is completely flawless.

Just like white diamonds, pink diamonds can range from flawless to (heavily) included. It is a gemstone that would give beauty and harmony to the world. Only 0.0001% of the diamonds in existence are pink. Pink Diamond – $1.19 million per carat Australia’s largest pink diamond Source: Rio Tinto After twenty minutes of intense bidding from eight potential buyers, the piece sold for $27.44 million to Cartier, the original designer of the necklace. The “Hutton-Midivani Necklace”, which consists of 27 large, top quality jadeite beads, did just that. The mineral is dense, with a specific gravity of about 3.4.

It has a Mohs hardness of about 6.5 to 7.0 depending on the composition. Jadeite is a pyroxene mineral with composition NaAlSi2O6. Jadeite is the purest, rarest, and most vivid gemstone in the Jade family.

Precious stones names