Grandidierite

Grandidierite
$65.00
Item number: 1

Grandidierite From Madagascar .47 CT


Grandidierite from Madagascar is one of the world's rarest and most sought-after gemstones, prized for its vivid bluish-green to greenish-blue hues and strong trichroic properties. Originally discovered in 1902 at Cape Andrahomana, the region near Tranomaro remains the premier source for gem-quality transparent crystals. 

 

Key Characteristics

 

  • Color & Pleochroism: Displays remarkable trichroic pleochroism, showing distinct colors depending on the viewing angle: dark blue-green, dark green, and colorless (or pale yellow).
  • Hardness: Rates at a durable \(7\frac{1}{2}\) on the Mohs scale, making it suitable for certain jewelry like pendants or earrings. 
  • Transparency: Varies from opaque to translucent, with fully transparent crystals being exceptionally rare and highly valued by collectors. 

 

 

Geology & Mining

Grandidierite is a magnesium-iron aluminum borosilicate. The most significant gem-grade material comes from pegmatites and metamorphic rocks in the Anosy region of southern Madagascar. While microscopic deposits are found elsewhere in the world, facetable material greater than a single carat predominantly originates from Malagasy mines. 

 

Market & Valuation

Because of its extreme scarcity, grandidierite is primarily a collector's stone. 

 

  • Cabochons: Translucent material cut into cabochons is more accessible but still commands a premium.
  • Faceted Stones: Clean, facetable, and transparent stones over 1 carat are exceedingly rare and can be priced significantly based on clarity and color intensity.