Ametrine is bi-colored crystalline quartz, which possesses a purple region and a yellow region within a single crystal. During their formation in nature, the two extremities of these crystals were exposed to differing temperatures, thus leading to differing iron oxidation states and resulting in differing colors. However, these colored zones may be separated by a narrow transitional region of colorless rock crystal within some stones.
The name is a portmanteau of the various names for purple and yellow quartz, namely amethyst and citrine. An alternative name for the gem is bolivianite, as almost all genuine natural ametrine is sourced in Bolivia. However, the material can also be produced semi-artificially by heating part of a natural amethyst crystal. At the same time, many cheap ametrines in the marketplace are fully synthetic stones from Russian laboratories.
Healing of ametrine
Ametrine calms the mind by clearing stress and tension from the head. Balances and soothes emotions and relieves depression. Ametrine overcomes prejudice by enhancing compatibility and acceptance of others. It stimulates creativity and supports taking control of one’s own life. Strengthens concentration, bringing clarity, and harmonizing perception and action. Ametrine instigates change and eases the transition.
Ametrine strengthens the immune system and aids the autonomic nervous system. It heals physical, mental and emotional exhaustion. Alleviates allergies and digestive disorders.
Crystal lore holds that ametrine offers its wearer powerful benefits. Since amethyst is associated with feminine energy and citrine is thought to crystallize masculinity, combining the two represents a balance of yin and yang, which some believe can be a balm to relationships. The stone’s duality is also said to promote harmony internally and externally, from integrated left- and right-brain thinking, to stimulating cooperation.
How is Ametrine formed?
The formation of ametrine owes to the unique location of Aniha Mine above a zone of hydrothermal activity. Where jets of superheated, mineral-bearing water strike the mine’s dolomitic limestone, quartz deposits containing amethyst, citrine, ametrine, and other quartz specimens have formed.
Ametrine derives its color from iron content, which depending on its state of oxidation at the time of the crystal’s formation, results in either a purple or golden color. Deposits often form parallel purple and golden quartz bands, sometimes with a band of clear quartz in-between. An ideal example of ametrine flaunts purple and gold prominently with a cut perpendicular to the c-axis, the point from which the two color zones radiate out.
Ametrine Characteristics
- Hardness: 7
- Transparency: Translucent to transparent
- Chemical composition: SiO2
- Crystal system: Hexagonal
History of Ametrine
According to legend, the Ayoreo Indian tribe of eastern Bolivia knew about the bicolor quartz crystals over 500 years ago. Perhaps the earliest formal documentation of natural quartz crystals with the zonal coloring of purple and yellow is in a 1925 issue of American Mineralogist. These were basal sections of quartz crystals with color sectors alternating between purple and yellow.
Reports of a quartz gemstone of mixed purple and yellow color produced anywhere in the world began in the 1960s from vague localities in Brazil, Bolivia, and Uruguay. Because the material was not attributed to a specific mine, some people believed it was produced synthetically, produced by treating amethyst or mined illicitly.
In 1989, changes to Bolivian mining laws allowed gemstone mining in eastern Bolivia, and a company, Minerales y Metales del Oriente S.R.L., obtained exclusive mining rights to a few thousand acres. Their property included a mine location with evidence of a long history of illicit mining. To establish credibility in the gemstone trade, the company invited geologists and gemologists to the mine. It allowed them to confirm for themselves that the ametrine and citrine produced there were natural.
Today, their Anahi Mine is the world’s only important commercial source of natural ametrine and Anahita (a clear variety of quartz with a very light tint of lilac). The mine also produces amethyst, citrine, and bicolor materials, a combination of amethyst and clear quartz (bi-color amethyst) or citrine and clear quartz (bicolor citrine).