SASSOLITE

    Class : Carbonates, nitrates, borates
    Subclass : Borates
    Crystal system : Triclinic
    Chemistry : H3BO3
    Rarity : Rare

Sassolite ; natural boric acid, and a rare mineral of certain volcanic fumaroles (the "soffionis" of Tuscany in particular), also present in certain borate deposits. It owes its name to its discovery location : Sasso (Italy). Sassolite occurs in small white to gray tabular crystals, sometimes light brownish, or in flattened lamellae. It is a fragile mineral (hardness of 1), light (density of 1.48), soluble in water and whose perfect cleavage further increases its fragility. It is a marginal ore of boron.

Main photo : Sassolite from Vulcano, Eolie Islands, Italy © Christophe Boutry

Sassolite in the World

Sassolite is known in efflorescence with small crystals in the fumaroles of Italian volcanoes (Vesuvius, Vulcano, Sasso). It is also found in the United States, in the hot springs and fumaroles of California (The Geysers, Sulphur Bank), and in the borate deposits of Boron and Death Valley.

Right photo : Sassolite from Anna Mine, Cologne, Germany © Thomas Witzke


Sassolite in France

Sassolite is not present in the French underground.

Twinning

Twinning is known on the [001] axis.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 1
Density : 1.46 to 1.50
Fracture : Undetermined
Streak : White

TP : Transparent
RI : 1.340 to 1.459
Birefringence : 0.119
Optical character : Biaxial -
Pleochroism : None
Fluorescence : None

Solubility : Water

Magnetism : NoneRadioactivity : None