1. Minerals Dr. R. B. Schultz

2. The earth is made of rocks, which are in turn made of minerals. In this part of the course we'll learn how to identify common minerals and rocks. In order for something to be classified as a mineral, it must meet five (5) criterion: Minerals are: · 1. Naturally occurring, · 2. Inorganic, · 3. Have known chemical compositions · 4. Have definite physical properties. 5. Are solid · They are usually (although not always) crystalline.

3. Common uses include: Aluminum--packaging, transport, building Beryllium--gemstones, fluorescent lights Copper--electric cables, wires, switches Feldspar--glass and ceramics Iron--buildings, automobiles, magnets Calcite--toothpaste, construction http://www.mii.org/commonminerals.php ** minerals can be elements or compounds **

4. Mineral Classification Minerals are classified based on chemical composition and crystal structure.

5. Mineral Classification: Chemical Composition Minerals are made of different ions bonded together. Ions are charged atoms  Cations are positively charged whereas  Anions are negatively charged Common ions in earth's crust: O - most common ion (anion) Si, Al, Fe, Ca, Na, K, Mg, (Cations) Minerals are made mainly of these ions. The number of each kind of atom in the molecule determines the minerals properties

6. Mineral Classification: Crystal Structure Crystal structure depends on sizes of and charges on ions Polymorphs -- same chemical composition, different crystal structures Calcite and argonite http://www.outreach.canterbury.ac.nz/resources/geology/page2.shtml

7. Mineral Classification: Groups Silicates: Most common mineral group (contain silicon and oxygen)  Quartz, Feldspars, Ferromagnesian  96% of Earth’s crust Non silicates: do not contain silicates or oxygen  Carbonates, halides, oxides, sulfates, sulfides, native elements

8. Minerals are identified by their key characteristics hardness crystal shape (form) luster color streak cleavage/fracture density (specific gravity) special properties - -reaction to acid -- fluorescence -- salty taste --magnetism

9. Mineral Hardness Ability to scratch another mineral Mohs scale from 1 (talc) to 10 (diamond) Quartz (most common mineral and most dust particles) is 7 http://mineral.galleries.com/minerals/elements/diamond/diamond.htm

10. Hardness Geologists rank minerals according to hardness using the Moh's scale Moh's Hardness Scale 1.0 TALC 2.0 GYPSUM 2.5 FINGERNAIL 3.0 CALCITE 3.5 COPPER PENNY 4.0 FLUORITE (Note the spelling!) 5.0 APATITE 5.5 STEEL KNIFE BLADE/GLASS PLATE 6.0 ORTHOCLASE FELDSPAR 7.0 QUARTZ 8.0 TOPAZ 9.0 CORUNDUM (RUBY) 10.0 DIAMOND

11. Crystal Shape (Form) External structure due to internal arrangement of the atoms Six basic groups of shapes, with about three dozen variations http://www.minerals.net/mineral/carbonat/aragonit/aragoni1.htm

13. Luster Describes how light reflects off the surface Main categories are “metallic” and “non- metallic” Non-metallic includes “dull,” glassy,” waxy,” “pearly,” and others http://www.minerals.net/mineral/sulfides/pyrite/pyrite2.htm

14. Non-metallic mineral Metallic mineral

15. Color results from ability to absorb some wavelengths and reflect others some minerals have characteristics colors others vary due to chemical differences or impurities (atoms mixed inside the main elements) http://www.minerals.net/mineral/carbonat/calcite/images/4assortd.htm

16. Streak Color of the powder when rubbed on a “streak plate” (unglazed porcelain) Streak does not vary even if color does Some paint is based on powdered minerals (streaks). http://www.minerals.net/mineral/oxides/hematite/hematit6.htm

17. Mineral cleavage/fracture Some minerals split along flat surfaces when struck hard--this is called mineral cleavage  correspond to zones of weak bonding in the crystal structure. Other minerals break unevenly along rough or curved surfaces--this is called fracture A few minerals have both cleavage and fracture

18. Cleavage To describe cleavage, one must determine the number of unique cleavage planes (directions) and their angle with respect to each other (e.g. salt breaks into cubes, with cleavage in 3 directions, all at 90 degrees) NO cleavage

19. Density (Specific Gravity) All minerals have density (mass / volume) Specific Gravity is the density of the mineral compared with density of water http://www.minerals.net/mineral/elements/gold/gold1.htm

20. Special Characteristics– the “Acid Test” Carbonates react with dilute HCl and other acids by fizzing or bubbling (releasing CO2 gas)

21. Special Characteristics-- Fluorescence Some minerals will glow when placed under short-wave or long-wave ultraviolet rays Franklin and Ogdensburg NJ are famous for their fluorescent minerals http://www.sterlinghill.org/Tour%20information.htm

22. Special Characteristics-- Salty Taste DO NOT TASTE MOST MINERALS! Example: Halite http://mineral.galleries.com/scripts/item.exe?LIST+Minerals+Halides+Halite

23. Special Characteristics-- Magnetism Many iron minerals will produce an invisible magnetic force field “Lodestone” was used by Vikings more than 1,000 years ago as compasses http://www.minerals.net/mineral/oxides/magnetit/magneti4.htm

24. Minerals Links (NAGT) An extensive listing of mineral links arranged by topic from the National Association of Geology Teachers (NAGT). Minerals Links (University of Würzburg) An extensive listing of mineral links including mineral descriptions and thin section images. Minerals (Mineralogical Society of America) The Mineralogical Society of America web site offers a good, general description of mineral properties, classification, etc. directed primarily toward K-12 grade students. Minerals (Trinity Mineral Company) Beautiful photos of rare minerals offered for sale by the Trinity Mineral Company. Minerals Information (USGS) United States Geologic Survey (USGS) statistics and information on the worldwide supply, demand, and flow of minerals and materials essential to the U.S. economy, the national security, and protection of the environment. Minerals on the Internet A wide variety of minerals-related sites sorted into relevant categories from Tasa Graphic Arts, Inc. Mining and Mineral Resources A great source for information about mining of mineral resources, mining news and trends, etc. National Mining Association The National Mining Association (NMA) represents the mining industry, mining equipment manufacturers, and other mining-related businesses, throughout the United States. Periodic Table of the Elements In addition to listing a wealth of information about each element, this location also lists and describes numerous compounds.

25. 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).

26. 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 Virtual Rock Bag http://comp.uark.edu/~sboss/vrockbag.htm#minerals