The main mineral components of granite include pyroxene, plagioclase, a little olivine, biotie and trace magnetite. It is precise in structure with black luster and through hundreds of millions years aging, it is of uniform texture, nice stableness, high intensity and rigidity, and can maintain a high precision under heavy weight. So granite is applicable to the works of industrial production and laboratory measurement.

The precision of the Jingda granite surface plates is in line with the standards of advanced countries.
Tolerance of planeness: Standard
JB/T7975-1999
Grade 000 = 1 × ( 1+d/1000 ) μm
Grade 00 = 2 × ( 1+d/1000 ) μm
Grade 0 = 4 × ( 1+d/1000 ) μm
Grade 1 = 8 × ( 1+d/1000 ) μm