Certificate number 38-1821-CO-PR-8451-16







Certificate number38-1821-CO-PR-8451-16
Issue date2016-05-11
Mineral SpecieCorundum
VarietySapphire
Mineral SpecieCorundum
Variety Sapphire
OriginNatural
Chemical composition          Aluminium oxide
Crystal system Rhombohedral
Habit Hexagonal bypiramid in different inclinations. Both ends of many crystals are capped by flat basal faces
ColourAccording to GIA GEmSet: G 7/1 green, dark, grayish
Cutting StyleOval
Measurements9.04x7.01x3.97 mm
Weight2.46 ct
LusterVitreous
TransparencyTransparent
Refractive indices1.770 - 1.762
Birrefringence0.008
Optic sign-
Hardness9 Mohs
CleavageNone
Density3.90
Absortion spectra absorciónDue to iron
Picture
CommentsStraight colour bands.
Tiny particles forming feathers. Extremately tiny particles forming feathers. Darkfield illumination, 40X.