Certificate number 31-1821-CO-PR-8451-16







Certificate number31-1821-CO-PR-8451-16
Issue date2016-05-11
Mineral SpecieCorundum
VarietyRuby
Mineral SpecieCorundum
Variety Ruby
OriginNatural - glass-filled treated
Chemical composition          Aluminium oxide
Crystal system Rhombohedral
Habit Hexagonal prism with rombohedral faces
ColourAccording to GIA GEmSet: slpR 7/3 slightly purplish red, dar,very slightly grayish
Cutting StyleOval
Measurements4.82x2.66x7.20 mm
Weight2.34 ct
LusterVitreous
TransparencyTransparent
Refractive indices1.770 - 1.762
Birrefringence0.008
Optic sign-
Hardness9 Mohs
CleavageNone
Density4.02
Absortion spectra absorciónDue to chromic oxide
Picture
CommentsThis gem have been treated with glass fissure filling. Fissure filling material may be unstable to elevated temperatures and to chemical agents. Special care should be taken when cleaning or reparing jewelry items set with fissure filled corundum.
Small rounded crystals altered by heating and colour flashes revealing the glass filled fractures. Darkfield illumination, 15X. Filling material concentrated along fissures. Darkfield illumination, 40X.