UHH Mineralogy

GEOL 212: Physical and Optical Mineralogy

CRYSTALLOGRAPHY Crystal Morphology and Forms



Handout on Crystal Forms

Isometric Crystal Forms to Know

Hexagonal, Tetragonal, Orthorhombic, Monoclinic, and Triclinic Forms to Know

READING ASSIGNMENTS
NESSE:
Read pages 24-37. Look at the drawings of the major forms and be sure you can recognize them. The main forms are listed on pages 26-28. Pay particular attention to the compound forms at the end of the chapter.
Read pages 36-38 about crystal habit. This is the general shape that crystals attain.

MINERALOGY TUTORITALS CD. In the Crystal Classes software, pay particular attention to the models and examples of real crystals given for each of the crystal classes. The animations are particularly good at showing the relationship of crystal axes and their relative angles to crystal forms.

THINGS TO KNOW:

  • Know what form and habit are. Be able to define and tell the difference.
  • Know the principle forms that are listed. Be able to identify them if given.
  • Be able to use the list of symmetry tips to place a form in the appropriate system.

    OPTIONAL READING

    Read the pages for each of the crystal systems (Isometric-Triclinic) paying particular attention to the forms and their relationship to crystallographic axes on the following web site.
    Mike and Darcy Howard's Web Crystallography Course


    Glance at the models of crystals on this page again and see if you can identify some of the forms.
    Crystallography Web Page

  • If you have comments or suggestions, email me at kenhon@hawaii.edu

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