trigonal Simulant turquoise simulant
Dyed Magnesite (Turquoise Simulant) (Dyed Magnesite (Blue))
Formula MgCO3 (magnesite; magnesium carbonate; dyed blue)
Crystal Structure
#! Species: Dyed Magnesite (MgCO3; turquoise simulant)
#! System: Trigonal (-3m)
#! Habit: Massive granular; dyed blue
trigonal[-3m]:{10-10}@1.0 + {0001}@0.4
trigonal
-3m
{10-10} {0001}
Quick Facts
Hardness
3.5
Specific Gravity
2.98
Refractive Index
1.509
Optical Character
Uniaxial -
Physical Properties
- Crystal System
- trigonal
- Hardness (Mohs)
- 3.5
- Specific Gravity
- 2.98
- Cleavage
- Perfect rhombohedral {1011}
- Fracture
- Conchoidal
- Lustre
- Vitreous to pearly
Optical Properties
- Refractive Index
- 1.509
- Birefringence
- 0.191
- Optical Character
- Uniaxial -
- Fluorescence
- Variable
Origin & Identification
- Origin
- Simulant
- First Produced
- 1980
- Diagnostic Features
- Very high birefringence 0.191 (double shadow on refractometer; unique identifier); effervescence in warm dilute HCl (carbonate vs phosphate turquoise); SG ~3.00 heavier than turquoise 2.60-2.90; dye bleeding at fractures; acetone removes dye; FTIR carbonate absorption ~1400 cm-1
Characteristics
Colours
Blue to blue-green (dyed); white when undyed
Common Inclusions
Dye bleeding at fractures and vugs
Notes
Natural magnesite (MgCO3) dyed blue to simulate turquoise; trigonal -3m (calcite structure type). Produced primarily in China and Eastern Europe. No dedicated peer-reviewed DOI resolved for dyed magnesite specifically; curriculum-standard simulant knowledge from Read 7th ed. (DOI 10.4324/9780080507224) [PARTIALLY_SUPPORTED]. Key diagnostic features: (1) high birefringence 0.191 (vs turquoise which shows very low birefringence); refractometer shows double shadow edge or two RI values (e~1.509, w~1.700) if flat face available; (2) effervescence with warm dilute HCl (MgCO3 is a carbonate; turquoise phosphate does not effervesce) — destructive but definitive; (3) dye bleeding at fractures; (4) acetone swab removes dye; (5) FTIR carbonate spectrum (~1400 cm-1 strong CO3 absorption vs phosphate of turquoise); (6) SG ~3.00 HEAVIER than turquoise 2.60-2.90 (opposite direction vs howlite). Note: SG relationship is reversed from dyed howlite — magnesite sinks where turquoise and howlite float in similar heavy liquids.
Related Minerals
Other minerals in the trigonal system
