KYANITE

Kyanite is a polymorph with two other minerals; andalusite and sillimanite. A polymorph is a mineral that shares the same chemistry but a different crystal structure with another, or other, minerals. Kyanite is an attractive mineral that has a near sapphire like blue color in some especially nice specimens. Kyanite has a unique characteristic in that it has a wide variation in hardness, in the same crystal. The hardness of kyanite is approximately 4.5 when scratched parallel to the long axis of the crystal and approximately 6.5 when scratched perpendicular to or across the long axis. Other minerals usually have variable hardness on different crystal faces due to a different concentration and oreintation of the atoms in the structure. Diamond is one such mineral, a fact gem cutters take advantage of often.

PHYSICAL CHARACTERISTICS:

Colour is blue usually but also can be white, grey or green. Colour is often not consistent throughout the crystal and can be blochy or in streaks.
Lustre is vitreous to almost pearly.
Transparency crystals are transparent to translucent.
Crystal System is Triclinic; bar 1
Crystal Habits include flat, pinacoid dominated, prismatic crystals often embedded in metamorphic rocks and quartz veins.
Cleavage is good in one direction parallel to the flat pinacoid face.
Fracture is splintery.
Hardness is approximately 4.5 when scratched parallel to the long axis of the crystal and approximately 6.5 when scratched perpendicular to or across the long axis.
Specific Gravity is approximately 3.58+ (above average)
Streak is white.
Associated Minerals are biotite, staurolite, garnets, quartz, andalusite and sillimanite.
Other Characteristics: Sometimes intergrown with staurolite.
Notable Occurrences include Brazil; North Carolina and Georgia, USA; Switzerland; Russia; Serbia; India and Kenya.
Best Field Indicators are crystal habit, colour, lustre and unusual hardness.

Metaphysical properties: Physical: hearing. General: energy. Assists: finance.