STIBICONITE

    Class : Oxides and hydroxides
    Subclass : Oxides
    Crystal system : Cubic
    Chemistry : Sb3O6(OH)
    Rarity : Fairly common

Stibiconite is the most common oxidation mineral of primary antimony minerals, particularly stibnite. It is therefore found in the superficial parts of antimony deposits, very often associated with other secondary antimony minerals, particularly kermesite; it makes up most of the "antimony ochres", a generic term for secondary antimony minerals with a yellowish tint. Its name comes from the Latin stibium (antimony) and the Greek konis (powder), thus emphasizing the often powdery appearance of the mineral and its chemical composition. Stibiconite most commonly occurs in masses and coatings of earthy appearance of yellow to yellowish white color, covering the surface of primary antimony minerals, sometimes completely replacing them (pseudomorph). It is an ancillary ore of antimony.


Main photo : Stibiconite pseudomorph after stibnite from Catorce, San Luis Potosi, Mexico © Connor Williams

Stibiconite pseudomorph after stibnite from Catorce, Mexico © Don Windeler
46 cm stibiconite pseudomorph after stibnite from Xikuangshan, China © Rob Lavinsky
Stibiconite from Clara Mine, Germany © Michael Förch
Stibiconite pseudomorph after stibnite from Massiac, St-Flour, Cantal, France © Robin Fialip

Stibiconite in the World

Beautiful stibiconite pseudomorphs after stibnite are known in the classic deposit of Real de Catorce (San Luis Potosi, Mexico), where the crystals, often grouped in radiate aggregates, reach 30 cm. Crystals equivalent to 50 cm are known in Xikuangshan (Hunan, China). Similar pseudomorphs, but of more modest size are also reported in Yugoslavia (Kostajnik, superb crystals of 15 cm) and in Tuscany (Italy)

Stibiconite in France

In France, stibiconite is known in pseudomorphs after stibnite in Lubilhac and Mercoeur (Haute-Loire) and in the antimony mines of St-Flour (Cantal). It is reported in many antimony deposits.

Twinning

No twinning known for this mineral species.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 5.5 to 7
Density : 3.3 to 5.5
Fracture : Undetermined
Streak : White to yellow

TP : Translucent to transparent
RI : -
Birefringence : 0
Optical character : None
Pleochroism : None
Fluorescence : None

Solubility : Acids

Magnetism : NoneRadioactivity : None