Sea foam soft neon-blue Grandidierite Gemstones

Gemstones, Grandidierite -

Sea foam soft neon-blue Grandidierite Gemstones

Grandidierite are seafoam and deep ocean blue gemstones from a now depleted deposit discovered in 2014 near the town of Tranomaro in southern Madagascar.

Relatively unknown, Grandidierite is extremely scarce often appearing on lists of the worlds’ 10 rarest gemstones.

REFRACTIVE INDEX 1.583 - 1.639

If you are after a ring set with this stone please DM me as I have several round and oval shaped, and a few emerald cut available.


Grandidierite comes in beautiful transparent greenish blues and rich translucent bluish greens. While small, eye-clean gemstones have been faceted in minuscule quantities, inclusions are a characteristic trait of Grandidierite. Grandidierite is so scarce that gems of almost any size, color or clarity will find a ready market. Grandidierite inclusions, needle-like channels, and parallel growth planes makes it challenging to cut. Nevertheless, quality of cut is very important as a skilled lapidary can locate Grandidierite inherent eye-visible inclusions in a way that minimizes their impact on beauty.

Grandidierite (Grand-die-deer-ite) was named after French explorer and naturalist Alfred Grandidier (1836–1912) who studied the natural history of Madagascar. An extremely rare magnesium iron aluminous borosilicate, Grandidierite was first discovered at the cliffs of Andrahomana on the southern coast of Madagascar. Grandidierite is bluish green to greenish blue, appearing bluer the more iron it contains. Grandidierite displays trichroic pleochroism, showing three different colors depending on the viewing angle: dark blue-green, colorless (sometimes very light yellow), or dark green. Since its discovery in 1902, most gem-quality Grandidierite has been translucent. Cabochons cut from these crystals look very attractive with some even appearing ‘Jade-like’. Recent discoveries of transparent crystals in Sri Lanka’s Kolonne region (2000) and a new deposit in Madagascar (2014) have resulted in beautiful, faceted gemstones.