silicates
Heliodor
Be3Al2Si6O18
- Also known as
- golden beryl
- Crystal system
- hexagonal
- Hardness
- 7.5–8 on the Mohs scale
- Lustre
- vitreous
- Colour
- Yellow to greenish yellow
- Where it forms
- In granite pegmatites, as with other beryls.
- Chiefly from
- NamibiaUkraineBrazilMadagascar
Why it is that colour
Iron in the ferric state. Irradiation deepens the colour and heating removes it, and both treatments are used commercially.
Safety
Safe to handle; beryllium dust from cutting is the hazard.
Where it comes from
Namibian and Ukrainian pegmatites are the classic sources. Modest commercial volumes.
Historical use
Named in 1910 from the Greek for gift of the sun, on the discovery of the Namibian deposits. Like morganite, an early twentieth-century commercial name.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
Worth knowing
Heliodor is included as the fourth beryl in a row, because the run makes the point better than any argument. Emerald, aquamarine, morganite and heliodor are one mineral. Their prices differ by three orders of magnitude, their supposed meanings are entirely unrelated to one another, and the physical difference between them is which trace metal happened to be in the fluid.
If the meanings tracked the material, they would all be the same.
Identity checked against IMA-CNMNC master list, June 2025.