cubic Composite assembled stone
Garnet-Topped Doublet (Doublet)
Formula Variable (almandine garnet crown + glass pavilion)
Crystal Structure
cubic
m3m
Quick Facts
Hardness
6.5
Specific Gravity
3.0
Refractive Index
1.73
Optical Character
Isotropic (crown)
Physical Properties
- Crystal System
- cubic
- Hardness (Mohs)
- 6.5
- Specific Gravity
- 3.0
- Lustre
- Vitreous
Optical Properties
- Refractive Index
- 1.73
- Birefringence
- 0
- Optical Character
- Isotropic (crown)
Origin & Identification
- Origin
- Composite
- Diagnostic Features
- Visible junction plane between crown and pavilion (red ring when immersed), garnet crown may show garnet spectrum, pavilion is glass (gas bubbles, swirl marks), different lustre between crown and pavilion, flattened bubbles near junction
Characteristics
Colours
RedBlueGreen (pavilion colour determines face-up colour)
Common Inclusions
Junction planeGas bubbles in pavilionRed ring in immersion
Related Minerals
Other minerals in the cubic system
