Yellow Beryl
Yellow beryls have a colour ranging from pale shades of lemon and yellow to deep yellow and yellow-orange (golden) colours. All shades of yellow may have green overtones.
Yellow beryl - may describe all yellow stones, but may refer to pale to mid-yellow colours when 'golden yellow' or 'hediodor' is not stated. Honey yellow has also been used as a description.
Golden beryl - may describe bright yellow-orange colours and not the weaker yellow and yellow-green tones.
Heliodor - may describe yellow-green coloured beryl, where the yellow colouring may be of varying shades. The name hediodor is Greek for 'Gift or present from the sun'.
Heliodor is often used to describe all yellow beryls in the gem market.
Properties of the Gemstone and Additional Information
| Gemstone type: | Varieties of the species Beryl. |
| Crystal System: | Hexagonal |
| Chemical Composition: | Berylllium aluminium silicate - Be3Al2(SiO3)6 |
| Colour: | lYellow to golden, greenish-yellow. May also be lemon or honey coloured. |
| Lustre: | Vitreous |
| Pleochroism: | Dichroic: distinct |
| Dispersion: | Low |
| Hardness: | 71/2 - 8 on the Mohs' scale. |
| Toughness: | Fair |
| Cleavage: | Very imperfect |
| Density in gm/cc: | 2.68 to 2.74 |
| Double refraction: | Yes |
| Refractive index: | 1.564 - 1.596 |
Common Treatments
Pale yellow material may be irradiated to improve the colour saturation.