Rubby caption of the nearest to gem quality, which may be cured by heating process to turn turn to gem quality.
Al2o3+Fe,Ti,Cr[c].
-Medium dark red variety.
-Vitreous to adarmantine luster.
-Hardness : 9.
-Density: 3.99 - 4.1(usually near 4.00).
-Optics: o=1.757 - 1.768.
e= 1.765 - 1.776.
-Unlaxial (-)
-Birefringence 0.008 - 0.009.
-Dispersion; 0.008(low).
-Pleochroinsm: very pronounced.
-Intense luminescence and distinctive in identification.