Opal stone is found in southern Australia and is characterized by the following physical and chemical properties:
Physical properties
- Figure nodules / locket blocks / small veins
- Silicate minerals group
- White scratching
- Hardness 6
- The color is multicolour / the price is black
- Bright
- Transparent / semi-transparent
- Vitreous / glossy
Chemical properties
- Refractive index 1.37 / 1.47
- Density 1.9 / 2.3
- The chemical formula is silica gelatin