IXIOLITE

    Class : Oxides and hydroxides
    Subclass : Oxides
    Crystal system : Monoclinic
    Chemistry : (Ta,Mn,Nb)O2
    Rarity : Rare

Ixiolite is a complex oxide with tantalum and niobium dominant in granitic pegmatites. Its structural formula incompletely reflects the composition of this mineral which may also contain small amounts of tungsten, titanium, zirconium, uranium and scandium. Its name was inspired by the character from Greek mythology Ixion, who, with Tantalus, was condemned by Zeus to eternal punishment. This highlights the similarity between this mineral and tantalite. In its deposits, ixiolite is a usual companion of microlite, cassiterite and tapiolite. It is a dark gray to black mineral which can form roughly rectangular prismatic crystals sometimes of large size (up to 10 cm) but occurs mainly in irregular grains and masses.


Main photo : Ixiolite from In den Dellen quarries, Eifel, Germany © Volker Betz

Ixiolite from Helen Beryl Mine, South Dakota, USA © Harold Moritz
Ixiolite from Namivu Pegmatite, Mozambique © Kelly Nash
Ixiolite from Namivu Pegmatite, Mozambique © Donald Doell
Ixiolite from Vez-Dara River Valley, Tajikistan © Stephan Wolfsried

Ixiolite in the World

Ixiolite is particularly known in pegmatites from Finland (Kemiö), Zimbabwe (Bikita), Canada (Tanco), Australia (Wodgina), Brazil (Araçuai, Minas Gerais), Mozambique (Muiâne) and Helen Beryl Mine (South Dakota, USA).

Ixiolite in France

In France, ixiolite is known in Montebras (Creuse), Puy-les-Vignes (Haute-Vienne) and in the pegmatites of Collioure (Pyrénées-Orientales).

Twinning

A twin is known on {103}.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 6 to 6.5
Density : 7.03 to 7.23
Fracture : Irregular
Streak : Brown

TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None

Solubility : -

Magnetism : NoneRadioactivity : Low