Grandidierite 0.91 ct – Rectangle Cut, Madagascar

This grandidierite weighs 0.91 ct and comes from Madagascar. It is worked in a rectangular cut and is untreated — at almost one carat it is among the larger stones this material yields at all.

The rectangular cut makes use of the length of the rough and loses little substance in doing so. With a material that rarely yields large clear pieces, every tenth of a carat that does not end up in the grinding slurry counts.

About grandidierite

Grandidierite was discovered in Madagascar in 1902 by Alfred Lacroix and named after the French explorer Alfred Grandidier. For decades the mineral was known almost exclusively in a cloudy, opaque form — facetable, clear material remained the exception and still comes almost entirely from southern Madagascar.

Its colour lies between blue-green and green-blue and comes from iron in the crystal lattice. The pronounced trichroism is striking: depending on the viewing direction, the same stone appears colourless, blue-green or dark green. With a Mohs hardness of 7 to 7.5, grandidierite is considerably more robust than many other collector stones; a distinct cleavage nonetheless demands care when cutting and setting.

Specifications

• Stone type: grandidierite
• Weight: 0.91 ct
• Origin: Madagascar
• Cut shape: rectangle
• Treatment: none, untreated
• Cutting: our own workshop
• Location: Austria
• Availability: unique piece, one only

Further single pieces from the same material can be found under Grandidierite, rare species beyond it under More gemstones. Would you like your own rough stone cut, or an existing stone reworked? We take that on in our workshop — more under Services.