RUBY


All facts and figures taken from the GIA

RUBY

Ruby is the most valuable variety of the corundum mineral species, which also includes sapphire. Rubies can command the highest per-carat price of any colored stone. This makes ruby one of the most important gems in the colored stone market. In its purest form, the mineral corundum is colorless. Trace elements that become part of the mineral’s crystal structure cause variations in its color. Chromium is the trace element that causes ruby’s red color.


MINERAL: Corundum
CHEMICAL COMPOSITION: Al2O3
COLOR: Red
REFRACTIVE INDEX: 1.762 to 1.770
BIREFRINGENCE: 0.008 to 0.010
SPECIFIC GRAVITY: 4.00 (+/- 0.05)
MOHS HARDNESS: 9


Ruby is the birthstone for July and the gem for the 15th and 40th anniversaries.

FOUND WHERE

Precious_Gemstone_Where_Found_Ruby