SIZE : less than 1cm
less than 2cm.
less than 5cm
less than 10cm
Chemically(examination of KICET in the KOREA)
MnO 40.6%.
SiO2 11.1%.
CuO 0.51%.
BaO 0.2%.
SrO 0.29%.
Cr2O2 0.08%
As2O2 0.19%.
PbO 0.01%.
V2O5 0.12%.
S 0.04%.
ZnO 0.06%
Co3O4 0.06%
ZrO2 0.02%
Na2O 0.30%
MgO 0.59%
K2O 0.96%
CaO 1.53%
Fe2O2 15.8%
Al2O3 11.5%
NiO 0.09%
P2O5 0.03%
TiO2 0.62%