Characteristics of an Amethyst
Colors of the amethyst
Depending on the temperature used on the process, the color of the amethyst can also become clearer to a yellowish (in this case the stone receives the name of citrine) or to a pale violet. The quality and the places of origin of the stone can have incidence on the colorations acquired by it when exposed to heat; here are some parameters of the colorations obtained by exposition to heat:
- 450 ° C the crystal acquires a yellowish color
- 500 ° C the crystal acquires a deep orange (burnt amethyst)
- 600 ° C the crystal becomes very milky
The effect produced by heat is possible due to the oxidation of the amount iron contained on the stone. It is possible to retrieve the original coloration of the crystal by exposing it to radiation. What makes amethyst different from other stones treated with heat is that it has a purple-blue and reddish purple dichroism.
The amethyst does not expose enough quality when it is exposed to artificial light. It can be ob served with more precision when it is exposed to natural sunlight, particularly after dawn and before sunset, when the light is soft and warm.
An amethyst of excellent quality is fully transparent which means that light is able to pass through the stone without difficulty. A translucent variety of amethyst weaknesses a little bit the pass of light through it. The best quality of amethyst is the clean amethyst, which is free from any type of inclusions. Since the stone can be easily acquired, there is no reason to get a stone with impurities.
Due to the rugosity on the distribution of colors on the crystals, the amethyst is cut very often as a circular stone very well rounded in order to maximize the coloration of the stone. Some other cuts can be used when the stone color is distributed in a better way. The amethyst is available on a great variety of calibrated sizes and shapes, among them many fantasy designs.
Localization and deposits of amethyst
The most important deposits for this stone are located on Brazil, more specifically in “Palmeira”, “Rio Grande do Sul” and “Marabá”. Some other deposits can be found on Bolivia, India, Canada, Madagascar, Namibia, Mexico, Burma, Russia, Sri Lanka and United States.