______________is formed from sandstone.

___________soil contains clay, silt, sand and humus in the right proportion.

__________is the only rock that is used as a fuel.

A strong smelling compound used in LPG is called___________.

Pumice, Basalt, Tuff, Granite and obsidian are_____________rocks.

__________soil contains a large amount of sand particles and very small amounts of silt and clay.

Sandstone, Limestone, coal, shale and conglomerate are__________rocks.

Slate, Marble, Diamond, quartzite and gneiss are__________________rocks

__________is blue due to the presence of small amount of cobalt or titaniunm oxide.

____________is used in the manufacture of cement.