MINERAL GEM WORLD

KORNERUPINE ROUGH CRYSTALS

This is a nautral untreated specimen of a rare Kornerupien.

Weight 3.45 cts app

Size 7 x 6 x 4 mm app

Kornerupine is a rare boro-silicate mineral. It crystallizes in the orthorhombic - dipyramidal crystal system as brown, green, yellow to colorless slender tourmaline like prisms or in massive fibrous forms. It has a Mohs hardness of 7 and a specific gravity of 3.3 to 3.34. Its indices of refraction are nα=1.660 - 1.671, nβ=1.673 - 1.683 and nγ=1.674 - 1.684.

It occurs in boron-rich volcanic and sedimentary rocks which have undergone high grade metamorphism. It is also found in metamorphosedanorthosite complexes.