Rock+Cycle

Basalt



Basalt is made up from fine-grained interlocking crystals.It is black or dark grey in colour, and often contains vesicles – bubbles of gas trapped as the lava cooled.

Gabbro



Gabbro is made up from coarse-grained interlocking crystals.Its overall colour is dark grey but it often contains glassy or pale-coloured crystals of feldspar as well as dark minerals.

Pumice

Pumice is formed when gas-rich magma froths up to form a sort of “mousse”.

Granite

Granite is is made of coarse-grained (5mm or so) interlocking crystals.