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Crystals

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Crystals

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  1. Crystals

  2. The 7 different types of Crystals

  3. Cubic (Isometric) Crystals • Not always shaped like a cube • Isometric – three sideswith the same length, height and breadth • Can be shaped like a octahedron (8 sides) or dodecahedron (12 sides) • Salt is an example of a cubic crystal found in natural crystals ThinkQuest, 2013 http://library.thinkquest.org/C005277/Crystal.html Gardiner, 2007 http://www.windows2universe.org/earth/geology/crystal_shapes2.html

  4. Crystals with cubic (Isometric) structures Carrollite, Calcite Pyrite http://www.mindat.org/photo-364349.html http://www.mindat.org/photo-200876.html Fluorite http://www.mindat.org/photo-347085.html

  5. Trigonal Crystals • Four axes, with three that are equal in length and one that is longer/shorter • Similar to hexagonal crystals due to its physical shape, except trigonal structure is less defined • Quartz is one of the most common forms of trigonal crystals The Natural Saphire Company, 2013 http://www.thenaturalsapphirecompany.com/education/related-information/trigonal-crystals/ ThinkQuest, 2013 http://library.thinkquest.org/C005277/Crystal.html

  6. Examples of crystals with trigonal structure Ikranite Quartz http://www.mindat.org/photo-279048.html Magensite http://www.mindat.org/photo-456858.html http://www.mindat.org/photo-87813.html

  7. Tetragonal Crystals • When looking through a microscope there structure is very similar in shape to cubic crystals except they are longer in length • look like prisms and double-pyramids Gardiner, 2007 http://www.windows2universe.org/earth/geology/crystal_shapes2.html James, 2011 http://www.yourgemologist.com/crystalsystems.html

  8. Crystals with tetragonal structures Chantalite, Grossular Stolzite http://www.mindat.org/photo-38543.html http://www.mindat.org/photo-488253.html Sphalerite http://www.mineraltown.com/reports/7/7.php?idioma=2

  9. Monoclinic Crystals • Also form as prism shapes or double pyramids • They appear to have been titled which makes them look different to cubic and tetragonal crystals • Most common crystal structure • One of the least symmetrical structures Gardiner, 2007 http://www.windows2universe.org/earth/geology/crystal_shapes2.html James, 2011 http://www.yourgemologist.com/crystalsystems.html

  10. Crystals with monoclinic structures http://www.mindat.org/photo-173157.html Spurrite Samuelsonite http://www.mindat.org/photo-94165.html http://www.mindat.org/photo-449174.html

  11. Orthorhombic crystals • Also appear like double-pyramids (two stuck together) • Looks like tetragonal crystals, although the centre where the pyramids join is not a square Gardiner, 2007 http://www.windows2universe.org/earth/geology/crystal_shapes2.html James, 2011 http://www.yourgemologist.com/crystalsystems.html

  12. Crystals with orthorhombic structures Columbite (Mn) Adamite http://www.mindat.org/photo-6832.html http://www.mindat.org/photo-20752.html Walkerite http://www.mindat.org/photo-500205.html

  13. Hexagonal crystals • Six-sided - Looks like the hexagon shape, only in prism form • Sides may not always be even, but the crystal will still have six Gardiner, 2007 http://www.windows2universe.org/earth/geology/crystal_shapes2.html James, 2011 http://www.yourgemologist.com/crystalsystems.html

  14. Nasonite Crystals with hexagonal structures Hibonite http://www.mindat.org/photo-58813.html Milarite http://www.mindat.org/photo-169922.html http://www.mindat.org/photo-477006.html

  15. Triclinic crystals • Least symmetrical – no equal sides or angles • can be very strangely shaped Gardiner, 2007 http://www.windows2universe.org/earth/geology/crystal_shapes2.html James, 2011 http://www.yourgemologist.com/crystalsystems.html

  16. Crystals with triclinic structures Paradamite Yvonite http://www.mindat.org/photo-42400.html http://www.mindat.org/photo-478061.html Gormanite http://www.mindat.org/photo-306825.html

  17. Crystals according to their physical/ chemical properties Covalent Crystals • All the atoms share the electrons that form a bond to create a solid shape • “One big molecule” • High melting point Metallic Crystals • Individual metal atoms • Outer atoms flow freely around the structure/ shape • High melting point Campbell, 1998-2011 http://www.chemistry.co.nz/crystal_types.htm

  18. Ionic Crystals • No covalent (shared) bonds between atoms • Atoms held together by slow-moving force • Often have a hard structure, high melting point Molecular Crystals • Structure is soft, low melting point • recognizable molecules that are held together by hydrogen bonds • Sugar is a type of molecular crystal Campbell, 1998-2011 http://www.chemistry.co.nz/crystal_types.htm

  19. Snowflakes • Are an interesting form of crystal, known as Ice Crystals • Formed when water freezes up in the clouds • No two snowflakes are ever the same – each have their own beautiful and unique structure • Temperature has a big influence on the shape the snowflake will be, and since temperature is always changing, different snowflakes are always created • So tiny it is only possible to see their complete structure under a microscope (Kidzworld, 2013; Maki, 1993; Science for Kids, 2013).

  20. Examples of Snowflakes http://www.its.caltech.edu/~atomic/snowcrystals/photos/photos.htm

  21. References Campbell, HA. (1998-2011). What types of Crystals are there? Kiwi Web: Australia and New Zealand. Retrieved 22 October, 2013, from http://www.chemistry.co.nz/crystal_types.htm Chao, I. and Ralph, J. (1993-2013). Minerals by Crystal Systems. Mindat.org. retrieved 22 October, 2013, from http://www.mindat.org/crystalsystems.php Gardiner, L. (2007). Shapes of Mineral Crystals. Windows 2 Universe. Retrieved 22 October, 2013, from http://www.windows2universe.org/earth/geology/crystal_shapes2.html James, R. (2011). The Seven Crystal Systems. Your Gemologist. Retrieved 22 October, 2013, from http://www.yourgemologist.com/crystalsystems.html Kidzworld. (2013). All about Snowflakes. Retrieved 21 October, 2013, from http://www.kidzworld.com/article/1587-all-about-snowflakes Libbrecht, K. G. (1999). Snow Crystal photo gallery. Snow Crystals.com. Retrieved 24 October, 2013, from http://www.its.caltech.edu/~atomic/snowcrystals/photos/photos.htm Maki, C. (1993). Snowflakes, Sugar, and Salt. Crystals up close. Learner Publications Company: Minneapolis. Science For Kids. (2013). Crystals. Ducksters. Technological Solutions. Retrieved 21 October, 2013, from http://www.ducksters.com/science/crystals.php The Natural Saphire Company. (2013). Trigonal Crystals. Retrieved 22 October, 2013, from http://www.thenaturalsapphirecompany.com/education/related-information/trigonal-crystals/ ThinkQuest. (2013). Crystal Systems. Cubic Crystals. Retrieved 22 October, 2013, from http://library.thinkquest.org/C005277/Crystal.html