orthorhombic Sulfates
Celestine
Formula SrSO4
Crystal Structure
#! Species: Celestine
#! System: Orthorhombic (mmm)
#! Habit: Tabular to prismatic with multiple dome faces
orthorhombic[mmm]:{001}@1.0 + {011}@0.8 + {210}@0.5 + {102}@0.4
orthorhombic
mmm
{001} {011} {210} {102}
Quick Facts
Hardness
3.0
Specific Gravity
3.95
Refractive Index
1.619
Optical Character
Biaxial +
Physical Properties
- Crystal System
- orthorhombic
- Hardness (Mohs)
- 3.0
- Specific Gravity
- 3.95
- Cleavage
- Perfect {001}, good {210}
- Fracture
- Uneven
- Lustre
- Vitreous to pearly
Optical Properties
- Refractive Index
- 1.619
- Birefringence
- 0.010-0.011
- Optical Character
- Biaxial +
- Dispersion
- 0.016
- Pleochroism
- Weak in colored specimens (pale blue shades)
- Fluorescence
- Weak to moderate blue-white
Characteristics
Colours
Celestial blue (pale blue)ColorlessWhitePale yellowPale greenReddish
Localities
Madagascar (large geodes)Ohio (USA - Put-in-Bay)England (Bristol area)PolandLibyaMexico
Crystal Forms
pinacoidprismtabular crystals
Notes
Isostructural with barite (BaSO4); distinguished by lower SG and strontium flame test (crimson)
Related Minerals
Other minerals in the orthorhombic system
