Volcanic rock While still dominated by silicates, more primitive volcanic rocks have mineral assemblages with less silica, such as olivine and the pyroxenes. Bowen's reaction series correctly predicts the order of formation of the most common minerals in volcanic rocks. Occasionally, a magma may pick up crystals that crystallized from another magma; these crystals are called xenocrysts. Diamonds found in kimberlites are rare but well-known xenocrysts; the kimberlites do not create the diamonds, but pick them up and transport them to the surface of the Earth. Volcanic rocks are named according to both their chemical composition and texture. Basalt is a very
Lemei Rock around Lemei Rock include the Indian Heaven Wilderness, which is known for the high mountain meadows among its scattered volcanic peaks. The Pacific Crest National Scenic Trail passes north/south through the volcanic field and the Indian Heaven Wilderness, which is known for its lakes and views of four nearby volcanoes: Mount Adams, Mount Hood, Mount St. Helens, and Mount Rainier. Major trails at Lemei Rock are the Lemei Trail, which climbs up the east side of Lemei Rock; and Wapiki Trail, which descends from the Lemei Trail to the deep blue Wapiki Lake, the "crater lake" of Lemei Rock. The