Gemstone Glossary

Hauyne

Hauyne is a rare type of mineral. It is sometimes called Huaynite. It was discovered in 1807 on Mt Somma, among Vesuvian lavas, Italy by the French crystallographer, Mr. R. J. Hauy (1743-1822), and was named after him. The mineral has been found in a typically beautiful electric blue as well as green, red, yellow, and gray colors.

Hauyne belongs to the Sodalite mineral group, which is composed of minerals with a similar isometric structure and related chemistry. The Sodalite group is also a group within a group. Its members are also part of a larger group called the Feldspathoids, which are low-silica igneous minerals. Other members of the Sodalite group of minerals are Sodalite (the most common member of the group), Nosean, Lazurite and Hackmanite.



Hauyne is formed from Sodium Calcium Aluminum Silicate Sulfate [(Na, Ca) 48Al6Si6(O, S) 24(SO4, Cl) 1-2]. It has a hardness of 5 - 6 on the Moh’s Scale with a Specific Gravity of 2.4 - 2.5. Its crystals are vitreous and can be sub-transparent to translucent, often occurring as well-formed coarse sized crystals.

Huayne naturally occurs in igneous rocks low in silica and rich in alkalies such as volcanic rocks, which provide the chemical supply and the environment needed for the mineral to form. Apart from Mt Somma, Italy, occurrences of Hauyne have also been reported in Tasmania, Australia, and in Eifel and Schwarzwald in Germany.

As it is quite rare and has beautiful color, Hauyne is highly priced. Especially the specimens that have nice luster and a beautiful, deep sapphire-blue color.