Granites are coarse-grained blends of minerals, including quartz (the most ubiquitous grains of sand at the beach), feldspar (the commonest of all minerals in Earth’s crust), and mica (which ...

Those rocks are a coarse-grained, glassy, greenish-gray completely ... and are flecked with gray and black minerals not found in the Grand Marais eccentrics. To find the source of these enigmatic ...

A huge stash of reddish minerals from a cave in Ethiopia shows ... The later ochre was also coarse-grained, so instead of grinding it to powder the people tended to chip and cut it.

Rocks of broadly similar composition to the coarse-grained “lunar basalts” also occur here on Earth. These rocks are referred to as dolerite, and contain many of the same minerals. In a sample ...