Ilvaite is not a common mineral in rock shops.
Its crystals are usually not all that attractive, but some specimens are real standouts with well-formed crystals with a shiny black color and an opaque submetallic luster.
Its diamond-shaped crystals with wedge-like terminations can form very interesting specimens.
Ilvaite is a member of the Sorosilicate subclass of the silicate minerals.
Sorosilicates have an unusual basic unit of Si 2 O 7 .
This group of atoms is composed of two silicate tetrahedrons that share one oxygen giving the group an hourglass shape.
A fine specimen of ilvaite can be a valuable addition to anyones collection.
Color is normally black, but also brownish black to dark gray.
Luster is submetallic or resinous.
Transparency crystals are opaque.
Crystal System orthorhombic; 2/m 2/m 2/m
Crystal Habits include elongated crystals with an overall diamond-shaped cross-section and wedge-shaped terminations.
Also as platy crystals and in massive, compact and columnar specimens.