What is Charoite?

What is Charoite?
What is Charoite. Photo: ExoticCrystals   

This mineral is rare -- found only in Siberia. Wasn't even discovered until late 1970s!

Charoite is a rare silicate mineral, first described in 1978 and named for the Chara River.

Charoite is translucent lavender to purple in colour with a pearly lustre. Charoite is strictly massive in nature, and fractures are conchoidal. It has an unusual swirling, fibrous appearance, sometimes chatoyant, and that, along with its intense colour, can lead many to believe at first that it is synthetic or enhanced artificially.

Charoite mostly appears opaque in clarity but it may seem somewhat transparent in some cases Charoite’s mild to moderate chatoyancy, best seen in species with higher translucency, is one of the most desirable characteristics.

To this day the only source of charoite gemstones has been the Murun complex in the Sakha Republic, Siberia.

Occurrence: In potassic feldspar metasomatites at the contact of nepheline and aegirine syenites with limestones.

Charoite occurs in association with tinaksite and canasite.

Name: For the Chara River, Russia, near which it was discovered.

How is Charoite Formed?

Charoite forms from calcareous deposits transformed by heat, pressure and injection of special chemicals (alkali-rich intrusions of nephline syenite). This process is known as’ contact metamorphism’ and is thought to be a common phenomenon in geology. Given that the forming mechanism is quite simple, it has never been fully understood why charoite occurrences are uncommon and limited only to the small region from which they are mined.

Though reportedly discovered in the 1940s, it was not known to most of the world until its description in 1978. It is said to be opaque and unattractive when found in the field; a fact that may have contributed to its late recognition.

What is Charoite?
Photo: ExoticCrystals   
Class: Silicates
Subclass: Inosilicates
Lustre: Vitreous, Silky
Transparency: Translucent
Colour: Violet to deep lilac
Hardness: 5 - 6 on Mohs scale
Cleavage: Distinct/Good. Good in three directions
Crystal System: monoclinic
Crystal Habit is of fibrous interlocking crystal masses.
Fracture conchoidal.
Specific Gravity is approximately 2.5 - 2.8 (average)
Streak is pale purple.
Notable Occurrence is solely the Chary River at Aldan in Russia.
Best Field Indicators are color, locality and habit.
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