Gemstone :



Birthstone Month :

Crocidolite is not associated with any particular birthstone month.


Zodiac :

Crocidolite is not associated with any particular zodiac sign.


Chemical Symbol :



Chemical Make-up :

Crocidolite is a Sodium Iron Magnesium Silicate and a form of Asbestos. It is involved with the pseudomorphism of a few Quartz gemstone's, including Pietersite, Tiger's Eye, and Hawk's Eye. Pseudomorph is classified as a mineral having the outward appearance of another mineral that it has replaced by chemical action.


History & Lore :

Crocidolite was first described in 1815 by M.H. Klaproth under the name

'Blaueisenstein', meaning “blue ironstone”. In 1831 J.F. Hausmann gave it its present name.


The name Asbestos is derived from Greek which means “unquenchable” on account to its resistance to fire and heat.


Only about 4% of Asbestos consumed is Crocidolite.


Asbestos is commercially useful for a variety of reasons. It is a strong yet flexible mineral that will not burn. It conducts electricity poorly, insulates effectively, and resists corrosion. However, the mining and commercial use of Asbestos has decreased due to the mid-twentieth century discovery that it can cause numerous Lung Diseases when inhaled.


Availability :

Crocidolite is an available mineral but is rarely used commercially due to the health problems it can cause.


Sources :

The most noteworthy deposits of Crocidolite can be found in Austria, Canada, China, Russia, and South Africa.


Evaluation :

Crocidolite is the asbestiform variety of Riebeckite, and is rated at 5 - 5.5 on the Moh's Scale of Hardness. Crocidolite has often been referred to as the “Blue Asbestos” because it is strongly pleochroic, ranging through several shades of blue. The fibers in Crocidolite are made up of mineral crystals that look like chains and Crocidolite can usually bend beyond 90 degrees before breaking.


Though Crocidolite is rarely used commercially, it is an important mineral in the Pseudomorph transformation of several Quartz gemstones including Pietersite, Hawk's Eye, and Tiger's Eye. The pseudomorphism begins when Quartz becomes embedded between the fibers of the Crocidolite. During the transformation, the Crocidolite is completely dissolved, with the Quartz taking on its fibrous formations. This creates parallel lines within the gem which allows a play of light and movement, known scientifically as chatoyancy. The play of light that rolls across the surface is reminiscent of the eyes of a cat


Common Cuts :

Gemstone's displaying chatoyancy are most commonly and almost exclusively cut into cabochons. This is because a tall, round cut is required to maximize the chatoyancy effect most brilliantly.


Routine Enhancements :

There are no known enhancements for Crocidolite.


Care & Cleaning :

Care and cleaning does not apply with Crocidolite.