Hardness: 5.5 - 7
Density: 3.5 - 3.7
Habit: Massive aggregate, with striated faces.
Colours: Bluish white (typical)
| ||Crystal System: Triclinic|
Reaction with HCl: Unknown
Identification in hand sample:
Bladed habit, colour, and difference of hardness along and across cleavages
Forms in metamorphs, especially in gneisses and schists
Kyanite has a hardness of 6-7 across cleavage planes, but only 4-5 along cleavage planes. Colour is typical, yet other colours (gray, white or less commonly light green) do occur.