Origin
Southern and central Africa
Brazil, Colombia, Southern and central Africa
Color
Colorless, Greenish, Green, gray, Yellow
Greenish, Blue, Colorless, White, Green
Specific Gravity
3.21-3.38
3.08-3.12
Fracture
Irregular/uneven, Uneven
ConchoidalWalter Schumann
Cleavage
Perfect on {001}
{010} Perfect
Chemical Composition
Ca 2Al 3(SiO 4) 3(OH)Walter Schumann , Gemstones of the world (2001) More from other references
BeAlSiO 4(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Pleochroism
StrongArthur Thomas
Weak: colorless-(greenish) yellow
Transparency
Transparent
-
Refractive Index
1.670-1.734
1.650-1.677
Crystal System
monoclinic
Monoclinic Prismatic H-M Symbol (2/m) Space Group: P 21/a
Birefringence
0.006-0.011
0.019-0.025
Clarity
Transparent
TransparentUlrich Henn and Claudio C. Milisenda
Neurological
-
Enhances mental clarity and focus
Psychology
Empathy
Harmony
Healing
Emotional healing
Emotional healing
Qualities Associated
Empathy
Communication