Grandidierite Crystal — Large Example

$752.42
Chemical Formula(Mg,Fe)Al₃(BSiO₉)
Crystal SystemOrthorhombic
Mohs Hardness7–7.5
Specific Gravity2.98–3.00
LusterVitreous
TransparencyTransparent

Grandidierite was described in 1902 from Madagascar and for decades was represented in mineral collections by a handful of specimens from that original locality. Its teal-blue colo…

7 in stock

SKU: TC-GEM-0473
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Description

There are objects in this world that carry the weight of unimaginable time. Grandidierite was described in 1902 from Madagascar and for decades was represented in mineral collections by a handful of specimens from that original locality. Its teal-blue color comes from iron; it is strongly trichroic, showing blue-green, colorless, and dark blue-green from different directions. Facetable quality remained elusive until a new Malagasy find in 2014.

This specimen originates from Tranomaro, Anosy Region, Madagascar, one of the world’s most significant localities for this type of material. Collectors and scientists have drawn from this region for generations, and for good reason: the combination of geological conditions here produces specimens of exceptional quality and clarity.

Every specimen is unique. Photographs approximate the visual experience, but the real thing — its weight, its luster under a raking light, the way it catches the corner of your eye — can only be experienced directly.

Formation

This specimen formed through geological processes operating over timescales that dwarf human history. The specific combination of chemistry, temperature, pressure, and time at this locality produced material of exceptional quality that makes it a valued addition to any serious collection.

Locality

Grandidierite Crystal — Large Example from Tranomaro, Anosy Region, Madagascar. This locality is known for producing specimens of exceptional quality.

Collector Notes

Photograph with a neutral grey background to capture true color.