1 / 17

Crystal Forms

Crystal Forms. www.intenseexperiences.com/images/CaveofCrystals2.jpg. Crystal Forms. Minerals grow into specific shapes They usually crystallize into one of 6 forms Cubic Tetragonal Hexagonal Orthorhombic Monoclinic Triclinic. Axes of Symmetry.

balin
Download Presentation

Crystal Forms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Crystal Forms www.intenseexperiences.com/images/CaveofCrystals2.jpg

  2. Crystal Forms Minerals grow into specific shapes They usually crystallize into one of 6 forms Cubic Tetragonal Hexagonal Orthorhombic Monoclinic Triclinic

  3. Axes of Symmetry • Lines about which a mineral can be rotated through some angle which brings the object to a new orientation which appears identical to its starting position.

  4. Cubic • Crystals shaped like blocks • 3 axes of symmetry • All the same length • All perpendicular to each other

  5. Cubic Example: Pyrite http://www.treasuremountainmining.com

  6. Tetragonal • Crystals shaped like four-sided prisms and pyramids. • Three axes of symmetry • Two axes are the same length and lie on a horizontal plane. • The third axis is not the same length and is at a right angle to the other two. • All perpendicular to each another.

  7. Tetragonal Example: Zircon www.dkimages.com

  8. Hexagonal • Crystals are shaped like six-sided prisms or pyramids. • Four axes of symmetry • Three lie in the same plane, are the same length, and intersect at 120° angles. • The fourth axis is not the same length, and is perpendicular to other three.

  9. Hexagonal Example: Beryl www.palagems.com

  10. Orthorhombic • Crystals are short and stubby. • 3 axes of symmetry • All unequal lengths • All perpendicular to each other.

  11. Orthorhombic Example: Topaz http://www.collectorfinejewelry.com

  12. Monoclinic • Crystals are short and stubby with tilted faces at each end. • 3 axes of symmetry • All unequal lengths • Two axes lie in the same plane at right angles to each other. • The third axis is inclined.

  13. Monoclinic Example: Gypsum http://www.galleries.com/minerals/property/gyp_flu.gif

  14. Triclinic • Crystals are usually flat with sharp edges, with no right angles. • 3 axes of symmetry • All unequal lengths • None are perpendicular to one another.

  15. Triclinic Example: Feldspar www.yourgemologist.com

  16. Credits • http://www.sdnhm.org/kids/minerals/howto-form.html (information) • www.gemsociety.org/ wow/read2.htm (form model images) • http://www.georgehart.com/virtual-polyhedra/symmetry_axes.html (axes of symmetry definition

  17. ASSIGNMENT • PG 63 SHOWS THE SIX MAIN CRYSTAL SYSTEMS • YOU NEED TO MAKE 3-DEMENSIONAL MODELS OF THE 6 MAIN CRYSTAL SYSTEMS • MAKE SURE TO LABEL EACH MODEL WITH THE SYSTEM NAME AND YOUR NAME

More Related