Sillimanite and Hematite Optical Properties

Sillimanite

Hematite

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1 Optical Properties

1.1 Luster

Vitreous, Subadamantine, Silky

Not Available

1.2 Pleochroism

Colourless to pale brown to yellow

O = brownish red; E = yellowish red

1.3 Dispersion

NANA

0.007 1

1.4 Transparency

Transparent, Translucent

OpaqueHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references

1.5 Refractive Index

1.653-1.6852.690-3.220

1 3.25

1.6 Optic Character

Not Available

1.7 Crystal System

Orthorhombic

Trigonal

1.8 Birefringence

0.020-0.0220.280

0 0.296

1.9 Clarity

Transparent

OpaqueHerve Nicolas Lazzarelli

Sillimanite and Hematite Optic Character

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

Similar to their colors, Sillimanite and Hematite 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, Sillimanite is Translucent and Transparent while Sillimanite is Translucent and Transparent in appearance.