Star Beryl

Refractive Index : 1.583 – 1.577 (+0.017 – 0.017)

Optical Characteristic : DR, U-

Specific Gravity : 2.72 (+0.18 – 0.05)

Formula : Be3Al2Si6O18

Crystal System : Hexagonal

Variety/Species : Star Beryl

Species/Group : Beryl

Birefringence : 0.005 – 0.009

Dispersion : 0.014

Hardness : 7.5 to 8

Toughness : good

Ultrasonic : risky

Steam : risky

UV Long : Inert

UV Short : Inert

Pleochroism : 2 colors

Strength : weak

Pleochroism Colors : None

Heat : Avoid heating

Acids : Avoid hydrofluoric acid

Light : some may fade

Polish Luster : vitreous

Fracture : conchoidal

Fracture Luster : Vitreous to resinous

Clarity Type : N/A

Tones : N/A

Saturations : N/A

Cause of Color : Iron

Enhancements : none

Cleavage : Indistinct.

Color Range : Yellowish brown, black, yellowish, brownish, blackish

Transparency : Semitranslucent to opaque

Phenomena : Asterism, 6 ray star

Separations : Star Beryl from-

Identifying Characteristics and information
Six ray star but usually weak

Spectral Data
Yellow green: band at 4375. weaker band at 4330.

Trade Names and Misnomers
Star Beryl

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