Material

Work index

Material

Work index

Barite

4.28 - 6.24

Fluorspar

2.98 - 9.76

Bauxite

2.38 - 9.45

Granite

2.68 - 15.13

Coal

1.63 - 11.37

Graphite

1.75 - 45.03

Dolomite

2.82 - 11.27

Limestone

2.69 - 11.61

Emery

3.48 - 58.18

Quartzite

2.71 - 12.18

Columbite

3.94 - 10.81

Titanium ore

4.23 - 11.88

Tantalite

3.6 - 11.90

Silica sand

2.65 - 16.46

Soba-Wanka Pyrochlore Coltan

4.79 on the average