Needles, Black Hills, South Dakota

Go to slide: 1: Plutonic Rocks 2: Granite 3: Anorthosite 4: Pegmatite containing tourmaline 5: Thin section of porphyritic rock 6: Needles, Black Hills, South Dakota 7: Needles, Black Hills, South Dakota 8: Climber on granite at Joshua Tree National Park 9: Stone Mountain, North Carolina 10: Cliffs at Bon Echo Lake, Ontario 11: Yosemite Valley, California 12: Exfoliation crack in granite 13: Granite on peak in Sierras 14: Rock climbers at Arch Rock, Yosemite National Park 15: Climbers on El Capitan, Yosemite National Park 16: Granites in Joshua Tree National Park 17: Summit of Harney Peak, Black Hills, South Dakota 18: Zoned feldspar in thin section 19: Hornblende in thin section

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