Zirconolite
Black crystal aggregates of the rare zirconium mineral zirconolite.
General
CategoryOxide minerals
Formula
(repeating unit)
CaZrTi2O7
IMA symbolZrc[1]
Strunz classification4.DH.30
Crystal system2M polytype: monoclinic
3O polytype: orthorhombic
3T polytype: trigonal
Crystal class2M polytype: prismatic (2/m)
3O polytype: dipyramidal (mmm (2/m 2/m 2/m))
3T polytype: trapezohedral (3 2)
Identification
ColorBlack to brown, red
LusterResinous, sub-Metallic
StreakDark brown, brownish yellow
DiaphaneityTranslucent, opaque
References[2]

Zirconolite is a mineral, calcium zirconium titanate; formula CaZrTi2O7. Some examples of the mineral may also contain thorium, uranium, cerium, niobium and iron; the presence of thorium or uranium would make the mineral radioactive. It is black or brown in color.[3]

References