Zunyite - Encyclopedia

    Class : Silicates
    Subclass : Sorosilicates
    Crystal system : Cubic
    Chemistry : Al13Si5O20(OH,F)18Cl
    Rarity : Rare

Zunyite is a silicate present in highly aluminous shales, some hydrothermal veins and altered volcanic rocks. It owes its name to its locality of discovery : the Zuni mine in San Juan County, Colorado, USA. It forms very beautiful tetrahedral or pseudo-octahedral crystals up to 2 cm, frequently twinned, colorless, greyish white, light pink or brown. It is a mineral only reserved for the collection, but little known collectors.

Zunyite in the World

Zunyite occurs in good specimens in the Zuni mines near Silverton, Colorado, and Silver City, Utah. Beautiful pale pink millimetric crystals have been found in aluminous schists near Postmasburg in South Africa. The largest crystals come from Dome Rock Mountains near Quartzite, Arizona. Among the other localities of this mineral, note the beautiful transparent tetrahedrons of Kuni (Honshu, Japan) but also the salt dome of Qalat-e Bala, Hormozgan, Iran which supplied brown crystals with hematite of 15 mm (photo on the right), sometimes twinned.

Zunyite in France

Zunyite is not present in the French underground.

Twinned zunyite from salt Dome of Qalat-e Bala, Iran
Twinned zunyite from salt Dome of Qalat-e Bala, Iran
Twinned zunyite from salt Dome of Qalat-e Bala, Iran
Zunyite from salt Dome of Qalat-e Bala, Iran
© Louis Verschuren


Zunyite is commonly twinned on [111].

Fakes and scams

No fake inventories for this mineral species.

Hardness : 7
Density : 2.88
Fracture : Irregular 
Trace : White

TP : Opaque to transparent
RI : 1.592 to 1.600
Birefringence : 0
Optical character : -
Pleochroism : None
Fluorescence : None

Solubility : Insoluble

Magnetism : None
Radioactivity : None