Citrine
Citrine occurs naturally but is rare, most citrine is produced commercially by heat-treating amethyst or smoky quartz.
The name citrine comes from the naturally coloured stone that has a similar colour to the citrus fruit lemon. Citrine in the gem market is available in colours ranging from light yellow to golden yellow, to a deeper reddish and brownish yellow. The material often contains zones of darker and lighter colour.
Source locations for natural citrine include: Argentina, Brazil, Madagascar, Myanmar, Namibia, Russia, Scotland, Spain and the USA.
Properties of the Gemstone and Additional Information
| Gemstone type: |
A variety of crystalline quartz. |
| Crystal System: | Trigonal |
| Chemical Composition: | Silicon dioxide (SiO2) |
| Colour: | Light yellow to golden yellow, reddish and brownish yellow. |
| Lustre: | vitreous |
| Pleochroism: | Weak: Light yellow and deeper shades of yellow. |
| Dispersion: | Low |
| Hardness: | 7 on the Mohs' scale |
| Toughness: | Good |
| Cleavage: | None |
| Density in gm/cc: | 2.65 |
| Double refraction: | Yes |
| Refractive index: | 1.544-1.553 |
Common Treatments
Most citrine is produced by heat-treating amethyst or colourless smoky quartz. The bright yellow colour is only produced when a sufficient amount of iron in present the material. The amount required is rarely found in naturally occurring citrine, hence natural citrines are of pale colours.