Properties
- Mineral: Corundum
- Chemical composition: Al2O3 (Aluminium oxide)
- Colour: Red
- Refractive index: 1.762 to 1.770
- Birefringence: 0.008 to 0.010
- Specific gravity: 4.00 (+/- 0.05)
- Mohs Hardness: 9
- Phenomenon: Asterism ( Star effect)
About Ruby
Ruby is a pink to blood-red variety of the mineral corundum. The red color is caused mainly by the presence of the element chromium. The more the chromium the stronger the red color. Chromium can also cause fluorescence which intensifies the red color. Its name comes from the word ruber which means red in Latin. Ruby is the most valuable of coloured gemstones according to per carat price.