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.
BIRTHSTONES & ANNIVERSARIES
Ruby is the birthstone for July and the gem for the 15th and 40th anniversaries.
In Sanskrit, ruby is ratnaraj, meaning the king of gems.
Myanmar’s legendary valley of rubies; the source of many of the world’s most fabulous gems.
On May 12, 2015, a 25.59-carat ruby ring sold for $1,266,901 per carat, setting a new record at auction for a colored gemstone.
- 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