specification:
Volumetric Weight: 2690kg/m3
Water-absorbtion: 0.03-0.6%
Compression strength 145-174MPa
Flexure strength -
Attritive ability of rock 0.05-0.44g/cm2
microcline 25-47   plagioclase 20-38 Quartz  20 -45 Biotite  20-45 other  3-10