SiO₂

%

0.20(max)

Al₂O₃

%

77-79

Fe₂O₃

%

0.10(max)

CaO

%

0.3(max)

K₂O+Na₂O

%

0.20(max)

Apparent Porosity
(max)

6.00%

B.D.
(gms/CC) (min)

3.2

Melting Point

+SK 42 (1980^oC)

Moh's Hardness

8

Crystal Structure

Cubic of MgO-Al₂O₃

Crystal Phase

Spinel