trigonal Carbonates
Rhodochrosite
Formula MnCO3
Crystal Structure
#! Species: Rhodochrosite
#! System: Trigonal (-3m)
#! Habit: Rhombohedral crystals
trigonal[-3m]:{10-11}@1.0 + {01-12}@0.3
trigonal
-3m
{10-11} {01-12}
Quick Facts
Hardness
3.5
Specific Gravity
3.45
Refractive Index
1.597
Optical Character
Uniaxial -
Physical Properties
- Crystal System
- trigonal
- Hardness (Mohs)
- 3.5
- Specific Gravity
- 3.45
- Cleavage
- Perfect {1011} (rhombohedral)
- Fracture
- Uneven to conchoidal
- Lustre
- Vitreous to pearly
Optical Properties
- Refractive Index
- 1.597
- Birefringence
- 0.218-0.220
- Optical Character
- Uniaxial -
- Dispersion
- 0.015
- Pleochroism
- moderate: Pinkish-red / Orangy-pink (Best seen in transparent faceted material)
Characteristics
Colours
Rose pinkDeep pinkRedRaspberry redBanded pink/whiteOrange-pink
Localities
Colorado (USA - Sweet Home Mine)Argentina (Capillitas - banded)South Africa (N'Chwaning)PeruRomaniaJapan
Crystal Forms
rhombohedronscalenohedron
Notes
Extremely high birefringence; dissolves in warm dilute HCl with effervescence; too soft for ring use
Related Minerals
Other minerals in the trigonal system
