Topaz actually has an exceptionally wide color range that, besides brown, includes various tones and saturations of blue, green, yellow, orange, red, pink, and purple. Colorless topaz is plentiful, and is often treated to give it a blue color. Topaz is also pleochroic, meaning that the gem can show different colors in different crystal directions.
1768
The royal court in Portugal celebrates the discovery of Imperial topaz in 1768.
271 kilos
A transparent topaz crystal discovered in Minas Gerais, Brazil weighs an astounding 596 pounds.
10 MeV
Irradiating colorless topaz with electrons at energy of 10 million electron volts creates a sky blue color.
Facts
- Mineral: Topaz
- Chemistry: Al2(F,OH)2SiO4
- Color: Yellow, orange, brown, pink to red to purple red, blue, light green and colorless
- Refractive index: 1.619 to 1.627
- Birefringence: 0.008 to 0.010
- Specific gravity: 3.53
- Mohs Hardness: 8