Opal Diamond Erring Jewellery

Opal Diamond Erring Jewellery

By Mans Women Jeellery

Opal

Color Colorless, white, yellow, red, orange, green, brown, black, blue, pink

Crystal habit Irregular veins, in masses, in nodules

Cleavage None

Fracture Conchoidal to uneven

Mohs scale hardness 5.5–6

Luster Subvitreous to waxy

Streak White

Diaphaneity opaque, translucent, transparent

Specific gravity 2.15+0.08

−0.90

Density 2.09

Polish luster Vitreous to resinous

Optical properties Single refractive, often anomalous double refractive due to strain

Refractive index 1.450+0.020

−0.080

Mexican opal may read as low as 1.37, but typically reads 1.42–1.43

Birefringence none

Pleochroism None

Ultraviolet fluorescence black or white body color: inert to white to moderate light blue, green, or yellow in long and short wave, may also phosphoresce, common opal: inert to strong green or yellowish green in long and short wave, may phosphoresce; fire opal: inert to moderate greenish brown in long and short wave, may phosphoresce

Absorption spectra green stones: 660 nm, 470 nm cutoff

Diagnostic features darkening upon heating

Solubility hot salt water, bases, methanol, humic acid, hydrofluoric acid

References