Grandidierite Gemstone

Grandidierite Gemstone

Grandidierite was discovered by Alfred Lacroix in Southern Madagascar in 1902. However, he named it after the French explorer and scientist, Alfred Grandidier, who wrote extensively on the flora, fauna and geology of Madagascar. On the side note, a mongoose, four species of plants and a giant Boabab tree are also named after Grandidier.

Grandidierite gemstone is of a magnesium aluminum borosilicate chemical composition that is colored by traces of iron. It occurs in an orthorhombic crystal structure. Its color ranges from a lovely turquoise-blue, to sky blue and to pale green colors. The most sought after is the extremely rare transparent neon blue specimen.

Grandidierite has a hardness ranging from 7 to 7.5 on the Mohs scale with a good to perfect cleavage. It is transparent to opaque with a glass-like luster.

Grandidierite is pleochroic and thus under different light sources and viewed from different angles, it changes colors from yellow to green to blue and in some specimens to colorless.

Grandidierite as a mineral is not rare and for the most part is opaque. But the gemstone quality translucent specimens are very rare, and on the other hand, the transparent specimen is extremely rare and immensely valuable. Such quality cut can fetch $20,000 per carat!

Some opaque gemstone quality Grandidierite are cut and polished into cabochons. Eye-clean transparent specimens have been found. However, it requires the utmost skill of a lapidarist to cut and polish it into a gemstone due to its tendency to crack in two directions (known as cleavage) and also to cut it in such a way that maximises its display of pleochroism.

Most Grandidierite gemstones sold on the market come heavily included or with flaws. However, this trait doesn't diminish its value, instead it accentuates it.

Though it was first discovered in 1902, due to its extreme rarity, no one has seen or heard about it until 2019 when it was rediscovered close to the initial mines. Thus, little is known about its metaphysical properties.

However, crystal healers believed that the presence of iron in Grandidierite is empowering and it boosts confidence and improves critical thinking and clarity of mind. Additionally, its green to blue colors are traditionally associated with wealth, luck, inner peace and compassion.

Opaque and translucent specimens are cut into cabochons and these are quite affordable as compared to the transparent faceted gemstones.

Due to its rarity and the belief that the mines are soon to be exhausted within a year, prices of Grandidierite are exorbitantly high now.

Grandidierite is not known to be enhanced or treated and its colors are naturally found as it is unearthed by hand.

Grandidierite is the third most expensive gemstone in the world. The largest known Grandidierite of 78 carat is owned by Joseph Fam from Singapore.

Geographically, Sri Lanka and Madagascar were part of the same land mass at least 335 million years ago at the time of Pangaea or Pangea when the earth was a huge supercontinent. Thus, it is no surprise to find in these two islands the same gemstones such as Grandidierite, Rubies, Sapphires, Tourmalines, Garnets and many more.

Grandidierite is rated at 7.5 on the Mohs hardness scale so it is tough enough for everyday wear. However as with all gemstones and especially the rare and valuable Grandidierite, extra care should be taken due to its good to perfect cleavage. Clean it with very mild soapy water and a soft cloth. Rinse well all residues.

Tourmaline can look similar to Grandidierite. However, Grandidierite, more so the faceted gemstones come in small sizes and are heavily included. Apatite and Apophyllite are also similar to Grandidierite in rough form but they are softer than Grandidierite.

Grandidierite is number three in the list of the rarest gemstones on planet Earth. Other extremely rare gemstones include Poudretteite, Tanzanite, Benitoite, Red Beryl, Jadeite, Black Opal, Taafeite, Alexandrite and Painite.

Grandidierite has been found in small amounts in the United States, New Zealand, Antartica, Sri Lanka, and India. In 2014 a new Grandidierite deposit was found in Madagascar. However, it produces only few gemstone quality specimens. Madagascar and India, thus far, are the only places that have been found very small carat size transparent Grandidierite.