Igneous rocks made mostly of the mafic minerals hypersthene, augite, and/or olivine.
Rocks that are very rich in magnesium and iron, such as peridotites.
said of an igneous rock composed chiefly of the minerals hyper-sthene, augite, or olivine; a magnesium-rich rock with less than 45% silica (silicon dioxide). It is the typical composition of the earth's mantle.
Igneous (rock formed from molten or partially molten material) rock types composed chiefly of mafic (magnesium-iron) minerals.
Igneous rock composed essentially of iron and magnesium. Return to the top of the page. VEIN : An opening, fissure or crack in rock containing mineralised material.
an igneous rock containing no quartz or feldspar and less than 45% silica.
igneous rocks of mantle origin with low silica contents.
Igneous rock consisting essentially of ferromagnesian minerals with trace quartz and feldspar.
Rock that is rich in magnesium and iron content.