orthorhombic Sulfates
Barite
BaSO4
Crystal Structure
#! Species: Barite
#! System: Orthorhombic (mmm)
#! Habit: Tabular with prominent basal face
orthorhombic[mmm]:{001}@1.0 + {210}@0.8 + {110}@0.5
orthorhombic
mmm
{001} {210} {110}
Quick Facts
Hardness
3.0
Specific Gravity
4.3
Refractive Index
1.636
Optical Character
Biaxial +
Physical Properties
Crystal Systemorthorhombic
Hardness (Mohs)3.0
Specific Gravity4.3
CleavagePerfect {001}, good {210}
FractureUneven
LustreVitreous to resinous
Optical Properties
Refractive Index1.636
Birefringence0.012
Optical CharacterBiaxial +
Dispersion0.016
PleochroismWeak
FluorescenceModerate to strong white, yellow, or orange
Colours
ColourlessWhiteBlue (celestial blue)YellowRedBrown
Localities
England (Cumberland, Derbyshire)MoroccoUSA (Colorado, South Dakota)GermanyRomaniaChina
Common Inclusions
Sand inclusions (in desert rose)Fluid inclusionsColour zoning
Crystal Forms
pinacoidprism
Notes
Exceptionally high specific gravity (4.3-4.5) for a non-metallic mineral; used in drilling mud
Related Minerals
Other minerals in the orthorhombic system
