یاقوت
Ruby cristal.jpg
A naturally occurring ruby crystal
General
CategoryMineral variety
Formula
(repeating unit)
ایلومینا with کرومیئم, Al2O3:Cr
Crystal systemTrigonal (Hexagonal Scalenohedral) Symbol (-3 2/m) Space Group: R-3c
Identification
ColorRed, may be brownish, purplish or pinkish
Crystal habitVaries with locality. Terminated tabular hexagonal prisms.
CleavageNo true cleavage
FractureUneven or conchoidal
Mohs scale hardness9.0
LusterVitreous
Streakwhite
Diaphaneitytransparent
Specific gravity4.0
Refractive indexnω=1.768 - 1.772 nε=1.760 - 1.763, Birefringence 0.008
PleochroismOrangey red, purplish red
Ultraviolet fluorescencered under longwave
Melting point2044 °C
Solubilitynone
Major varieties
SapphireAny color except red
Corundumvarious colors
EmeryGranular

نگار خانہترميم