monoclinic Chromates
Crocoite
PbCrO4
Crystal Structure
#! Species: Crocoite
#! System: Monoclinic (2/m)
#! Habit: Elongated prismatic with adamantine lustre
monoclinic[2/m]:{110}@1.0 + {100}@0.7 + {001}@0.5 | elongate(c:3.0)
monoclinic
2/m
{110} {100} {001}
Quick Facts
Hardness
2.5
Specific Gravity
5.97
Refractive Index
2.31
Optical Character
Biaxial +
Interactive Preview
Open this crystal in the CDL Playground to rotate, export, and explore in 3D.
Open in PlaygroundPhysical Properties
Crystal Systemmonoclinic
Hardness (Mohs)2.5
Specific Gravity5.97
CleavageDistinct {110}
FractureConchoidal to uneven
LustreAdamantine to vitreous
Optical Properties
Refractive Index2.31
Birefringence0.37
Optical CharacterBiaxial +
PleochroismWeak (red to orange-red)
Colours
Orange-redRedHyacinth redYellow-orange
Localities
Tasmania (Australia - Dundas, Red Lead Mine)Russia (Urals - historic type locality)BrazilPhilippinesZimbabwe
Crystal Forms
prism (elongated)pinacoid
Notes
RI over refractometer limit; extremely high birefringence; contains lead - wash hands after handling
Interactive Preview
Open this crystal in the CDL Playground to rotate, export, and explore in 3D.
Open in PlaygroundRelated Minerals
Other minerals in the monoclinic system
Actinolite (Prismatic)
Ca2(Mg,Fe)5Si8O22(OH)2
Augite (Prismatic)
(Ca,Na)(Mg,Fe,Al)(Si,Al)2O6
Azurite
Cu3(CO3)2(OH)2
Chrome Diopside
CaMg1-xCrxSi2O6
Diopside
CaMgSi2O6
Dyed Howlite (Turquoise Simulant) (Dyed Howlite (Blue))
Ca2B5SiO9(OH)5 (calcium borosilicate hydroxide; dyed blue to simulate turquoise)