Black opals from Australia’s famous opal fields at Lightning Ridge scintillate colorful flashes of fire on a dark background. Ill-feelings and anxieties evaporate as soon as this most precious of opals appears on the scene.
Formula: SiO2 + H2O
Hardness: 5.5 – 6.5
Density: 1.97 – 2.22 g/cm3
Refractive Index: 1.37 – 1.47 (commonly 1.45)
Color: opal with a play of color and a black (dark)body color
Countries of Origin: Australia
Birthstone: April