amorphous composite assembled stone
Opal Doublet (Cabochon)
SiO2*nH2O on dark backing
Quick Facts
Hardness
5.5
Specific Gravity
1.9
Refractive Index
1.44
Optical Character
Isotropic (amorphous)
Crystal Structure
amorphous
Physical Properties
Crystal Systemamorphous
Hardness (Mohs)5.5
Specific Gravity1.9
LustreVitreous to resinous
Optical Properties
Refractive Index1.44
Optical CharacterIsotropic (amorphous)
PhenomenonPlay of colour
Origin & Identification
Origincomposite
Diagnostic FeaturesVisible dark backing when viewed from side, flat back, slightly different appearance from solid opal, adhesive layer may be visible at junction, profile view shows two-layer construction
Colours
Black opal appearanceVarious play of colour
Common Inclusions
Junction planeDark backing visible from sideAdhesive layer
Interactive Preview
Open this crystal in the CDL Playground to rotate, export, and explore in 3D.
Open in PlaygroundNatural Counterpart
The natural gem this composite imitates
Related Minerals
Other minerals in the amorphous system
