L. 9A AMphiboles.ppt

Amphibole minerals are found in igneous and metamorphic rocks. USGS Amphibole minerals form needle-like or prism-shaped crystals. The minerals collectively know as asbestos are members of the amphibole mineral group. by-nc: meganpru Most amphibole minerals are not asbestos. Inosilicates (chain) Comm...

Amphibole minerals are found in igneous and metamorphic rocks. USGS Amphibole minerals form needle-like or prism-shaped crystals. The minerals collectively know as asbestos are members of the amphibole mineral group. by-nc: meganpru Most amphibole minerals are not asbestos. Inosilicates (chain) Common Fe/Mg – bearing silicates Two common groups – Pyroxenes: single chains – Amphiboles: double chains Pyroxenes are common in MORB Amphiboles more common on continents because of weathering Structure Chains extend parallel to c axis Stacked in alternating fashion like pyroxenes Points face points and bases face bases Structure Chains extend parallel to c axis Stacked in alternating fashion like pyroxenes Points face points and bases face bases lamprophyre by-nc-sa: Ron Schott © Bruce Molnia, (Earth Science Image Bank) granite USGS USGS Amphibole is found in intrusive igneous rocks. granodiorite diorite by-nc-sa: Ron Schott Mount St. Helens Amphibole is found in extrusive igneous rocks. USGS USGS rhyolite dacite andesite USGS Amphibole is found in metamorphic rocks. Amphibole (dark) and plagioclase (light) crystals in amphibolite. schist by-nc-nd: GOC53 © Cornel Manecan (Earth Science Image Bank) gneiss amphibolite cut by dikes by-nc-sa: Ron Schott Greenstone belts, named for the green color of amphibole, contain metamorphosed igneous and sedimentary rock. by: kevinzim by-nc-sa: Ron Schott metamorphosed limestone with stromatalites metamorphosed pillow basalt The amphiboles in metamorphic rocks can form very long and thin crystals. Microscopic photograph of asbestos. public domain USGS (Earth Science Image Bank) ATSDR/CDC Most commercial asbestos comes from chrysotile, a fibrous variety of the mineral serpentine (amphibole). by-nc-nd: Niemster by-nc-nd: patricia imagines by-nc: AlbinoFlea Asbestos was used in older buildings as insulation, roofing material, and other heat or fire proof applications. by-nc-nd: maxnathans by-nc: Erik B by-nc-nd: Alain Bachellier by-sa: Michael Pereckas Asbestos removal is happening all over the world. by-nc-sa: James_C by-nd: amishah by-nc-sa: Ron Schott Amphiboles are an important component of many decorative building stones, where their colors contribute to the stones’ decorative pattern. by-nc-sa: mharrsch by-nc-sa: libraryman Jade is made of amphibole or pyroxene, and prized in Chinese, Maori and Aztec cultures. © StoneTrust (Earth Science Image Bank) by-nc-nd: Hunter333 by-nc-nd: sanofi2498 by-sa: cygnoir by-nc: Mister Wind-Up Bird Nephrite (an amphibole) and jadeite (a pyroxene) are nearly indistinguishable. by-nc-sa: Giant Gingko Amphibole group media rights Our notation Creative Commons Licenses public domain description (none) by by-sa by-nc-sa by-nd by-nc-nd GNU © GNU Free Documentation License Copyright. All rights reserved Many of the photos in this presentation were obtained through Flickr and Wikipedia. Funded by FIPSE and by the University of Minnesota. Compiled for Dr. Kent Kirkby, Department of Geology and Geophysics, by Kate Rosok, 2007. Each displayed image retains its original media rights. For educational purposes only; not to be used commercially.