Opal and Alabaster Optical Properties

Opal

Alabaster

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1 Optical Properties

1.1 Luster

Vitreous, Pearly

Not Available

1.2 Pleochroism

None

Not Available

1.3 Dispersion

NoneNone

0.007 1

1.4 Transparency

Transparent, Translucent, Transparent to translucent

Translucent

1.5 Refractive Index

1.37-1.521.520-1.530

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Trigonal

Not Available

1.8 Birefringence

Not Available0.010

0 0.296

1.9 Clarity

Transparent

Translucent

Opal and Alabaster Optic Character

Opal and Alabaster optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Opal and Alabaster Physical Properties like crystallographic symmetry, pleochroism,etc. in the crystal. Some of the optical properties are refractive index, luster, optic character, pleochroism etc. Prominent among these is Opal and Alabaster optic character. You might have noticed your gemologist rotating the gemstone while testing it. Rotating a gemstone along its optic axis helps in determining its optic character.

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Opal and Alabaster Transparency

Similar to their colors, Opal and Alabaster transparency can also be used as criteria for their primary identification. Although transparency cannot be the only criteria for gemstone identification, it can efficiently used in gemstone grading. Talking about their transparency, Opal is Translucent, Transparent and Transparent to translucent while Opal is Translucent, Transparent and Transparent to translucent in appearance.