Key to Grades

Ruby (R) / Blue Sapphire (B) / Yellow Sapphire (Y)
R-1.1, B-1.1, Y-1.1: Unheated.
R-1.2, B-1.2, Y-1.2: Dyed. Color concentration is seen in surface reaching cracks.
R-1.3, B-1.3, Y-1.3: Oil-filling is seen in surface reaching cracks.
R-2, B-2, Y-2: Heat Treated.
R-2.1, B-2.1, Y-2.1: Heat Treated along with Residue (flux) in surface reaching cracks and cavities.
R-2.2, B-2.2, Y-2.2: Heat Treated along with Glass Filling in surface reaching cracks and cavities.
R-2.3, B-2.3, Y-2.3: Heat Treated along with Residue (flux) & Glass Filling in surface reaching cracks and cavities.
R-2.4, B-2.4, Y-2.4: Heat Treated with titanium diffusion.
R-2.5, B-2.5, Y-2.5: Heat Treated with beryllium diffusion.
R-3, B-3, Y-3: Cavities filled with resin or some foreign substance.

Emerald (E)
E-1: Non – Treated
E-2.1: Oil filling is seen in surface reaching cracks.
E-2.2: Resin filling is seen in surface reaching cracks.
E-2.3: Resin & Oil filling is seen in surface reaching cracks.
E-3: Dyed. Color concentration is seen in surface reaching cracks.