معادن

Minerals

Dr. R. B. Schultz

Mafic silicate

Felsic silicate

Silica Tetrahedron

Oxygens
Silicon

Common non-silicate mineralsFluorite – used as a toothpaste additiveCalcite -- calcium carbonate -- Limestone is made of calcite. Dolomite -- calcium magnesium carbonate Gypsum -- calcium sulfate Galena -- lead sulfide Pyrite -- iron sulfide Halite -- sodium chloride (table salt)


How to Identify Minerals: Physical PropertiesGeologists determine the identity of an unknown mineral by describing its physical properties. They then use a reference book to find out what mineral has those properties. We will learn to describe the physical properties. 1. Habit refers to the overall shape of the mineral. Scientists use terms like: "equant" (3 dimensions of the mineral have about the same length, like a cube or sphere), “elongate" (one direction is long but the other 2 are short, like a pencil), or "platy" (one dimension is short, other 2 are long like a sheet of paper) Isolated tetrahedra & framework silicate minerals tend to be equant in habit; chain silicates tend to be elongate, sheet silicates are platy 2. Luster refers to the light reflected off of the mineral and its overall quality. Minerals can be termed: glassy, opaque, transparent, shiny, or most commonly: metallic and non-metallic. One of the first determinations a geologist must make is whether the mineral in metallic or non-metallic.

Non-metallic mineral

Metallic mineral

NO cleavage

MineralChemical compositionCrystalline structureIonsCationAnionSilicateMaficFelsicSilica tetrahedronSingle chainDouble chainSheet silicateFramework silicateNon-silicatePhysical propertiesHabitLusterStreakCleavageHardnessMoh’s Hardness Scale Key Terminology

Pertinent Web Sites

Amateur Mineralogy Links A very extensive listing of links to sites related to mineralogy. Ask a Geologist If you have questions, a professional geologist is here to help. Ecole des Mines de Paris Mineralogy Here are some beautiful mineral pictures from a museum in Paris. Gems and Precious Stones Jill Banfield's (University of Wisconsin-Madison) integrated body of information about gems and gemstones. Gold Institute A good commercial site with a lot of information about gold. Gold Prospecting A good source for information about recreational gold prospecting. Mineral and Gemstone Kingdom This site contains a comprehensive list of minerals and their properties. Mineral and Rock Description (National Park Service) Mineral and rock photographs and descriptions from the National Park Service. Mineral Data Links Links to several mineralogy related Web sites. Mineral Descriptions and Images The Mineral Gallery is a constantly growing collection of mineral descriptions, images, and specimens, together with several ways of accessing these descriptions. Mineralogy and Petrology Research on the Web An extensive list of mineralogy and petrology resources on the Web. Mineralogy Database This extensive mineral database contains more than 5,000 pages of mineral data. There are 3,874 individual mineral species data descriptions. Mineralogy Links (University of Oxford) An extensive listing of mineralogy and minerals related sites. Mineral Identification Tutorial Mineral identification tutorial from Texas A & M University. Mineral Photographs A comprehensive collection of mineral and gemstone photographs from The Image. Mineral Resources Program (USGS) The USGS Mineral Resources Program is responsible for providing and communicating current, unbiased information on the occurrence, quality, quantity, and availability of mineral resources. Minerals Links (Houghton Mifflin) Links to several mineral sites, including class lecture notes, arranged by topic.


Periodic Table of the Elements II A great source for information on the elements. Resource Fact Sheets (USGS) United States Geological survey (USGS) activities in the natural resources theme area inventory the occurrence and assess the quantity and quality of natural resources. Activities also include monitoring changes to natural resources, understanding the processes that form and affect them, and forecasting the changes that may be expected in the future. Resources from Space University of Wisconsin course notes with links to several essays about resources from space. Resource Sustainability An essay that examines the future of Earth's resources. Rock and Mineral Collecting (USGS) Selected references on rocks, minerals, and gemstones from the United States Geological Survey (USGS). Rockhounds Information Page The Rockhounds Information Page offers many links to mineral and rock related Websites. Smithsonian Gem & Mineral Collection Images of mineral and gemstone specimens found in the Smithsonian Institution. (Not an official Smithsonian site) Society for Mining, Metallurgy and Exploration, Inc. The Society for Mining, Metallurgy, and Exploration (SME) is an international society of professionals in the minerals industry. Society of Economic Geologists The Society of Economic Geologists, Inc. (SEG) is an international organization of individual members with interests in the field of economic geology. State Minerals Information (USGS) Statistics and information on the supply, demand, and flow of minerals and materials essential to the U.S. economy, the national security, and protection of the environment from the United States Geological Survey (USGS).

Technical University of Clausthal This site at a German university also shows some excellent mineral pictures. Virtual Atlas of Opaque and Ore Minerals This site provides over 400 full colour photomicrographs of the major ore-forming associations and opaque minerals in non-mineralized rocks. It describes typical examples of each material from many classical localities throughout the world. For each association there is a listing of the major (and important minor) primary ore minerals, alteration products and gangue, typical textures, a brief discussion of the geology of the association and a list of references. World Lecture Hall (University of Texas at Austin) The World Lecture Hall features links to online courses in the United States and Canada. Simplest to use for Mineral I.D. Lab: Virtual Rock Bag http://comp.uark.edu/~sboss/vrockbag.htm#minerals