Home > African Minerals – April 25 > MS1199 Grandidierite

Grandidierite


Grandidierite is a rare borosilicate of magnesium and iron. Like lazulite and kyanite, grandidierite owes its blue-green coloration due to its iron content. Lacroix (1902) named the mineral after Alfred Grandidier (1836-1912), who wrote a comprehensive encyclopedia on the biodiversity, geography, and anthropology of Madagascar. While the mineral has been known for over a century, it rarely finds itself on the collector market. There are numerous world localities where the mineral occurs in silica poor metamorphic rocks.

This is a matrix example, where the blue-green grandidierite crystals reach 3.3 cm and occur embedded in feldspar. There is a 1 mm zircon crystal embedded along the feldspar-grandidierite contact. Grandidierite is a metamorphic mineral, and as such does not show excellent crystal form. These grandidierite grains are contacted, but nevertheless this is an attractive hand sample. There is some minor chipping of some grandiderite edges.

Price: $400

Item code: MS1199

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