HELIODOR, the yellow variety of beryl
- VARIETY OF: Beryl
, Be3 Al2 Si6 O18 .
- USES: Gemstone.
- COLOR: various shades of yellow.
- INDEX OF REFRACTION: 1.57 - 1.60
- BIREFRINGENCE: 0.004 - 0.008
- HARDNESS: 7.5 - 8
- CLEAVAGE: one direction, poor.
- CRYSTAL SYSTEM: hexagonal
- Pleochroic: weak
Heliodor is the yellow variety of beryl, the "mother of gemstones".
Heliodor does not include golden colors which are given the apt name of golden beryl.
Other gemstone color varieties that belong to beryl include emerald (green), morganite
(pink), and aquamarine (blue).
Other colors of beryl are simply referred to by their color, such as in golden beryl and red beryl.
Heliodor is found in Madagascar, Brazil, North Carolina and California in the U.S., and in Middle Eastern countries and Russia.