Difference between revisions of "Template:Topaz"

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(Added "plane" to basal)
 
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| Habit || Prismatic with pyramidal/domed terminations
 
| Habit || Prismatic with pyramidal/domed terminations
 
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| Cleavage || Perfect, basal
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| Cleavage || Perfect, basal plane
 
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| Fracture || Sub-conchoidal to uneven
 
| Fracture || Sub-conchoidal to uneven

Latest revision as of 19:46, 9 February 2007

Topaz
Chemical composition Al2(F,OH)2SiO4
Crystal system Orthorhombic
Habit Prismatic with pyramidal/domed terminations
Cleavage Perfect, basal plane
Fracture Sub-conchoidal to uneven
Hardness 8
Optic nature Biaxial +
Refractive index 1.606-1.644
Birefringence 0.008 - 0.010
Dispersion Low, 0.014
Specific gravity 3.49 - 3.57
Lustre Vitreous
Pleochroism Distinct to strong (depending on body color)