KTENASITE

    Class : Sulfates, chromates, molybdates
    Subclass : Hydrated sulfates
    Crystal system : Monoclinic
    Chemistry : (Cu,Zn)5(SO4)2(OH)6 H2O
    Rarity : Rare

Ktenasite is a rare copper and zinc sulfate from the oxidation zone of base metal deposits. It was named in honor of the Greek mineralogist and geologist Konstantin Anton Ktenas. Ktenasite forms groups of tabular crystals no larger than a millimeter, of a dark blue-green color.

Main photo : Ktenasite from Jean Baptiste Mine, Kamariza, Lavrion, Greece © Fritz Schreiber

Ktenasite from Veneziana mine, Veneto, Italy © Matteo Chinellato
Ktenasite from Torrebelvicino, Veneto, Italy © Matteo Chinellato
Ktenasite from Glomsrudkollen Zinc Mines, Norway © OT. Ljøstad
Ktenasite from Cap Garonne, Var, France © Gérard Dubois

Ktenasite in the World

Ktenasite is only known in around twenty countries, including the Kamariza mine in Lavrion (Greece), where it is associated with blue serpierite and smithsonite. It is also found in two mines in Arizona (79 Mine and OH). Very pretty crystals are also known from the mines of Torrebelvicino (Veneto, Italy).

Ktenasite in France

Ktenasite is known at the Couloumier mine (Ariège), at St-Laurent-le-Minier (Gard) and at Cap Garonne (Var).

Twinning

No twins are known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 2 to 2.5
Density : 2.94 to 2.97
Fracture : Undetermined
Streak : Undetermined

TP : Transparent
RI : 1.574 to 1.628
Birefringence : 0.049 to 0.054
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : Acid, ammonia

Magnetism : NoneRadioactivity : None