Name |
|
Cordierite
(Dichroite) |
Chemistry |
|
Mg2Al3[AlSi5O18] |
Hardness |
|
7 |
Lustre |
|
greasy - vitreous |
Colour |
|
colourless, grey, violet, blue, brown |
Streak |
|
white |
Density [g/cm3] |
|
2.6 |
Crystal habit |
|
orthorhombic, crystals
rarely, short columnar |
Cleavage, Fracture |
|
fracture conchoidal |
other characteristics
and occurrences |
|
iolite = blue violet
(gemstone variety)
metamorphic mineral, primarily in gneiss |
 |
|
|