Grain Size
Large and Coarse Grained
Medium to Fine Coarse Grained
Fracture
Not Available
Uneven
Streak
White
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Dull to Grainy with Sporadic parts Pearly and Vitreous
Subvitreous to Dull
Cleavage
Not Available
Crenulation and Pervasive
Toughness
Not Available
2.4
Specific Gravity
2.6-2.7
2.86
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant