The color is considered dark if the rock appears as a dark gray to black (pyroxenes, the amphibole Hornblende, the mostly Ca-plagioclases near Anorthite, and Biotite mica. Density is a property that is proportional to the composition of the rock. The higher the amount of silica (felsic) the less dense the rock will be.
agriculture is thecultivation of land and breeding of animals and plants to provide food, fiber,medicinal plantsand other products to sustain and enhance life.
