When you hear the word IGNEOUS think of: Questions or ignite, fire, volcanoes, lava, suggestions molten rock, magma. contact: Separate Randy Bechtel mineral Randy.Bechtel What to look for: crystals @ncdenr.gov Granite – became solid inside the Earth Intrusive-inside the earth (Granite) • Crystals of different minerals (different colors & shapes) Easy to see large mineral crystals • Mineral crystals are easier to see (than in extrusive rocks). portal.ncdenr.org • The crystal surfaces sparkle or shine when seen in the sun /web/lr/earth- or bright light. science-outreach Extrusive-outside on the earth (Basalt) • Mineral crystals are harder to see (than in intrusive rocks). feldspars • The crystals are very, very small or may not be present at all. • These rocks can come from volcanoes and can look many different ways, from very small mineral crystals to lava with bubble holes to broken pieces of rock. Basalt – became solid on the surface of the Earth Difficult to see very, small mineral crystals Interlocking mineral quartz crystals in a granite. mica Pyroxene and amphibole other dark minerals Igneous - 1 Edited 11/1/13 Questions or suggestions contact: Randy Bechtel Environment where the rock formed: Food: Randy.Bechtel • Chocolate fountain @ncdenr.gov • These rocks were once totally molten • Melted chocolate bar or gummy bears portal.ncdenr.org • They crystallized (became solid) on the Earth’s /web/lr/earth- science-outreach surface or underground: • Swiss Cheese Lava (extrusive) – a volcano oozed or squirted the lava onto the Earth’s surface, cooled quickly and became solid. Magma (intrusive) – blob of magma rose (think of a lava lamp blob), became solid below the Earth’s surface, sometimes miles underground, and cooled very slowly. Igneous - 2 Extrusive - Erupted as LAVA & other pieces ON the Earth’s SURFACE Light Colored Dark Colored Igneous Rocks Igneous Rocks Questions or In- between suggestions contact: Have a lot of silica Does not have a lot of silica Randy Bechtel (Intermediate) (Felsic-feldspar & silica) (Mafic-magnesium & iron) Randy.Bechtel @ncdenr.gov Rhyolite Dacite Basalt portal.ncdenr.org /web/lr/earth- science-outreach Intrusive – Never erupted. Blobs Granite Diorite Gabbro of molten rock MAGMA solidified BELOW the Earth’s SURFACE (think lava lamp blob) Igneous - 3 .