distinguish between a finegrained black limestone and basalt
May 08, 2013· 14 Apr 2012 . Basalt is a darkcolored, finegrained, igneous rock composed . The difference between basalt and gabbro is that basalt is a finegrained . It is usually black or dark green in color and composed mainly of the minerals plagioclase and augite. .. rock that is produced from the metamorphism of limestone.