Nepheline and Bertrandite Optical Properties

Nepheline

Bertrandite

Add ⊕

1 Optical Properties

1.1 Luster

Vitreous, Greasy

Vitreous

1.2 Pleochroism

Not Available

none.

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

Transparent, Translucent

TransparentAnthony et al, Handbook of mineralogy (2001)

1.5 Refractive Index

1.529-1.5471.583-1.614

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Hexagonal

Orthorhombic Pyramidal H-M Symbol (mm2) Space Group: Ccm21

1.8 Birefringence

0.003-0.004Not Available

0 0.296

1.9 Clarity

Transparent

TransparentAnthony et al

Nepheline and Bertrandite Optic Character

Nepheline and Bertrandite optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Nepheline and Bertrandite 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 Nepheline and Bertrandite 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.

Compare Red Gemstones

Nepheline Vs Pyrope Spessartine

Nepheline Vs Prase Opal

Nepheline Vs Pyrope

Nepheline and Bertrandite Transparency

Similar to their colors, Nepheline and Bertrandite 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, Nepheline is Translucent and Transparent while Nepheline is Translucent and Transparent in appearance.