|Mineral class||Struntz VIII/B.31 - 12. Neso - subsilicate|
|Habitus||Crystals shortprismatic. Also massive and fibric.|
|Cleavage|| indistinct. Fracture brittle, uneven.|
|Color||Brownish yellow to brownish green, greenish brown, grayish, white, blue and colorless.|
|Occurance|| Created by methamorphism of boron rich clay sediments.|
In the Reading Prong locality the peak metamorphism occured at 670-740 degrees celsius and at a pressute about 6.2-8 Kbar.
|Associates||Biotite, sillimanite, oligoclase, garnet, tourmaline.|
A member of the kornerupine group of minerals. It was long considered
to be a boron rich variety of kornerupine, but recent years analysis
showed it to be so special it finally in 1996 was considered to be an
The type locality of this mineral is in Waldheim, Sachsen, Germany, where it was found in 1886.
The Swedish sample of kornerupine in the museum of natural history were reexamined in 1996/97 ??? and found to consist of enough boron to be classed as a prismatine.
A rare mineral only known from a few localities in the world. |
| To silicate index.
|| Mineral group index.
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