Zirconolite

Zirconolite is a mineral, calcium zirconium titanate; formula CaZrTi2O7. Some examples of the mineral may also contain cerium, niobium and iron; the presence of the cerium would make the mineral radioactive. It is black or brown in color.
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General Information:
 Chemical Formula:
(Ca,Fe++,REE,Zr,Th)(Zr,Nb,Ti,Ta,Fe+++)Ti2O7
 Environment:
In pegmatites.
 Locality:
Fredriksvarn, Norway.
 Name Origin:
Named for the composition.
Physical Properties:
 Color:
black or brown.
 Density:
4.8
 Habits:
Striated - Parallel lines on crystal surface or cleavage face., Massive - Uniformly indistinguishable crystals forming large masses., Prismatic - Crystals Shaped like Slender Prisms ( e.g. tourmaline).
 Hardness:
6.5 - Pyrite
 Luminescence:
Non-fluorescent.
 Streak:
dark brown
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General Information:
 Chemical Formula:
Ca2Zn(AsO4)2·2(H2O)
 Composition:
(Molecular Weight = 459.41 gm)
Calcium 17.45 % Ca
Zinc 14.23 % Zn
Arsenic 32.62 % As
Hydrogen 0.88 % H 
Oxygen 34.83 % O 
 Empirical Formula:
Ca2Zn(AsO4)2·2(H2O)
 IMA Status:
Approved IMA
Physical Properties:
 Cleavage:
[???] Good
 Color:
colorless or white.
 Density:
3.75
 Diaphaniety:
Transparent
 Hardness:
3 - Calcite
 Streak:
white
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General Information:
 Chemical Formula:
(Ca,Fe,Y,Th)2Fe(Ti,Nb)3Zr2O7
 Environment:
In sanidinite.
 IMA Status:
Approved IMA
 Locality:
Monte di Procida, Campi Felgrei, Campania, Italy.
 Name Origin:
Named for its composition.
Physical Properties:
 Cleavage:
[???] Indistinct
 Color:
dark red or brown.
 Density:
4.7
 Diaphaniety:
Opaque
 Habits:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., ,
 Hardness:
5.5 - Knife Blade
 Luster:
Resinous
 Streak:
dark brown
More details...

General Information:
 Chemical Formula:
(Ca,Fe,Y,Th)2Fe(Ti,Nb)3Zr2O7
 Environment:
In sanidinite.
 IMA Status:
Approved IMA
 Locality:
Monte di Procida, Campi Felgrei, Campania, Italy.
 Name Origin:
Named for its composition.
Physical Properties:
 Cleavage:
[???] Indistinct
 Color:
dark red or brown.
 Density:
4.7
 Diaphaniety:
Opaque
 Habits:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., ,
 Hardness:
5.5 - Knife Blade
 Luster:
Resinous
 Streak:
dark brown
More details...