1. Minerals: Building blocks of rocks

2. Minerals: Building blocks of rocks Introduction What are minerals and how are they different from rocks? What are some of the physical and chemical properties of minerals? What is the most abundant mineral group? What do all minerals in this group have in common? What are some important nonsilicate minerals? When is the term ore used with reference to a mineral?

3. Minerals: Building blocks of rocks IntroductionDefinitions Minerals versus rocks rock – an aggregate of minerals aggregate – minerals occur together as a mixture each mineral retains its distinctive properties mineral – a naturally occurring inorganic solid that possesses a definite chemical structure, which gives it a unique set of physical properties

4. Minerals: Building blocks of rocks Introduction Minerals exhibit the following characteristics: naturally occuring inorganic solid definite chemical structure Definitions

5. Minerals: Building blocks of rocks IntroductionProperties of minerals Major properties of minerals: crystal form luster color streak hardness cleavage fracture specific gravity

6. Minerals: Building blocks of rocks IntroductionProperties of minerals Crystal form – external arrangement of the orderly internal arrangement of atoms

7. Minerals: Building blocks of rocks A supersaturated solution readily forms crystals Crystallization occurs when the KE of individual molecules decreases. IntroductionProperties of minerals Crystal form – clearly evident only when the mineral forms without space restrictions Crystals form as they overcome solvation forces Most minerals form under intense competition for space

8. Minerals: Building blocks of rocks IntroductionProperties of minerals Luster – appearance or quality of light reflected from the surface

9. Minerals: Building blocks of rocks IntroductionProperties of minerals Luster metallic luster submetallic luster nonmetallic luster vitreous pearly silky resinous earthy

10. Minerals: Building blocks of rocks IntroductionProperties of minerals Color – very unreliable diagnostic property due to impurities

11. Minerals: Building blocks of rocks IntroductionProperties of minerals Streak color of a mineral in its powdered form use a streak plate more reliable than color metallic (dense, dark streak) vs. nonmetallic

12. Minerals: Building blocks of rocks IntroductionProperties of minerals

13. Minerals: Building blocks of rocks IntroductionProperties of minerals Hardness resistance of a mineral to abrasion or scratching use the Mohs scale

15. Minerals: Building blocks of rocks IntroductionProperties of minerals Cleavage a mineral will break along weak bonds when stressed tendency of a mineral to break along planes of weak bonding cleavage is described by the number of planes formed and the angles in which these planes meet not all minerals have definite planes of cleavage

16. Minerals: Building blocks of rocks IntroductionProperties of minerals Some examples of cleavage

17. Minerals: Building blocks of rocks IntroductionProperties of minerals Fracture minerals that do not exhibit cleavage tend to fracture when broken conchoidal fracture – produces smooth curved surfaces other types of fracture (splinters or fibers) most minerals fracture irregularly

18. Minerals: Building blocks of rocks IntroductionProperties of minerals Some examples of fracture Fibrous fracture – note formation of parallel fibers Conchoidal fracture – note smooth curved surfaces

19. Minerals: Building blocks of rocks IntroductionProperties of minerals Specific gravity - compares the weight of a mineral to the weight of an equivalent volume of water

20. Minerals: Building blocks of rocks IntroductionMineral groups Silicates most common made of oxygen and silicon silicon-oxygen tetrahedron is the fundamental building block

21. Minerals: Building blocks of rocks IntroductionMineral groups Variants of the silicate structure addition of metals to stabilize structure (Fe, Mg, K, Na, Al, and Ca) sharing of oxygen atoms results to a variety of configurations single chains double chains sheets

22. Minerals: Building blocks of rocks IntroductionMineral groups

23. Minerals: Building blocks of rocks IntroductionMineral groups Variants of the silicate structure the ratio of oxygen to silicon atoms varies among the different silicate structures high or low silicon content based on this ratio important in the formation of igneous rocks families of minerals same structure but with varying amounts of metals olivine, (Mg,Fe) 2 SiO 4

24. Minerals: Building blocks of rocks IntroductionMineral groups Dark silicate minerals ferromagnesian silicates contains iron and/or magnesium dark color and greater specific gravity

25. Minerals: Building blocks of rocks IntroductionMineral groups olivine hornblende biotite

26. Minerals: Building blocks of rocks IntroductionMineral groups Light silicate minerals nonferromagnesian silicates contains Al, K, Ca, and/or Na light color and smaller specific gravity

27. Minerals: Building blocks of rocks IntroductionMineral groups Light silicate minerals feldspars – most common light silicates (most common mineral on Earth) orthoclase feldspar – has K ions plagioclase feldspar – has Na and Ca light color and smaller specific gravity quartz – consists entirely of silicon and oxygen

28. Minerals: Building blocks of rocks IntroductionMineral groups Nonsilicate minerals carbonate minerals (limestone) halite (table salt) gypsum (used in plaster, building materials) metal ores (Fe, Zn, Pb) native elements – free occurring, not in compounds (Au, Ag, C)

29. Minerals: Building blocks of rocks References http://www.diamondjewelersonline.com/ http://www.gfy.ku.dk/~flyvholm/Ice_crystals_02_07_04.htm http://itl.chem.ufl.edu/2041_f00/lectures/lec_i.html http://en.wikipedia.org/wiki/Pyrite http://www.gc.maricopa.edu/earthsci/imagearchive/quartz.htm http://www.geology.sfasu.edu/sld002.html http://www.essencesonline.com/Alaskan-gem.htm http://www.canadianrockhound.ca/2002/01/cr0206102_monte_bianco.html http://cmsc.minotstateu.edu/Labs/web%20minerals/Streak.html

30. Minerals: Building blocks of rocks References http://www.iun.edu/~geos/Zoran%20IUN/G%20101/Lecture%20Outlines/Minerals.htm http://www.its.caltech.edu/~atomic/snowcrystals/primer/primer.htm http://www.mandarava.com/Retail/Crystal_shop.htm http://www.marinmineral.com/africa5.html http://www.minresco.com/display/disp02.htm http://www.soes.soton.ac.uk/resources/collection/minerals/minerals/pages/M30-Talc.htm http://lpc1.clpccd.cc.ca.us/lpc/hanna/examspractice/geo10lab/mineralphotos/mineralphotosC.htm http://www.usoe.k12.ut.us/curr/science/sciber00/7th/earth/sciber/minerid.htm http://www.rocksandminerals.com/hardness/mohs.htm http://www.pitt.edu/~cejones/GeoImages/1Minerals/2SedimentaryMineralz/Calcite_Dolomite.html