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Steffen Weber has created a replacement version of JCrystal called
KrystalShaper that can produce paper models of the example crystals on the
crystallography section of Webmineral. Paper models for the 32 crystal
classes and 7 crystal systems have been reproduced in .pdf format. These models
can be printed on heavy card stock to construct a physical model. Please note:
the paper model forms may be simplified from the JCrystal forms to avoid
overly-complicated cut-outs.
Students may want to try and construct a physical model of the crystal forms
for illustration purposes. These models will help teach symmetry operations
needed to identify crystal forms. The student is encouraged to mark on the paper
models noting mirror planes and rotational axes.
Link to paper model PDF files: Isometric
Tetragonal Orthorhombic
Hexagonal Trigonal Monoclinic
Triclinic
Instructions:
- Select the paper crystal model by clicking on the thumbnail image. You may
want to try the crystal system models first because of the simpler shape.
- Print in landscape mode on Heavy Paper Card Stock (60-70 lb/ream) for best
results. You want paper about the thickness of a postcard. Use 8.5x11 or A4
size. For a larger model, you can use 11x17 or tabloid sizes if your printer
can handle the larger paper sizes.
- Cut along lines using a sharp scissors or a blade cutter (Exacto� knife)
on a cutting mat.
- Crease and fold the tabs and crystal faces along the pre-printed lines.
Use an awl or mechanical pencil tip (with the lead retracted) to crease the
paper along the lines.
- Test fold crystal form to check fit.
- Apply White Glue on Tabs, one pair at a time using Toothpick.
- Hold Tabs Together until Dry.
- Repeat for all Tabs.
Here is an e-mail I received from Uwe Kolitsch on referencing
brackets in mineral nomenclature.
Hi Uwe,
I was always a little fuzzy on the protocols for using ....[ { ( <..... in
mineralogical references. Thanks for the pointers. They didn't teach this stuff
in the dark ages when I took my mineralogy course. Or if they did teach it,
there were too many years between then and now when I needed to use it.
This is important stuff and I need to pay more attention. Since webmineral is
created from a database, all I have to do is modify the programs that create the
"data" and "Java" pages. I also need to review the supporting pages in the
crystallography section and be sure the brackets are correctly used. I will
probably modify the help pages to clarify the information you kindly provided.
Thanks,
Dave
Hi Dave,
I noted that crystal forms and faces/planes on webmineral are incorrectly
written (I hope my following advice is helpful):
Example1:
Schultenite - Cleavage: [010] Good
(should read: ... (010) Good or {100} Good)
Example 2:
Schultenite - Forms: [ 0 1 1] [ 1 2 1] [ 0 1 0] [ 1 4 0] [ 1 1 1] [ 1 3 0] [ 0 0
1]
(should read: Forms: {011} etc.)
There are some general rules:
- (Single) crystal faces/planes are written (...)
e.g. (110), (1-10) etc.
- Crystal forms are written {...}
e.g. {100} in the cubic system comprises the set of the following 6
symmetry-equivalent faces/planes: (100), (-100), (010), (0-10), (001) and
(00-1).
- Directions in a crystal (zone axes) are written [...] [ uvw ]
e.g., [100] = direction along the a-axis
- A set of all symmetry-equivalent direction is written <...> (e.g.,
<100> for halite = directions [100], [-100], [010], [0-10] etc.)
- [Note: d-spacings hkl are written without any parentheses (e.g., "the
311 reflection").]
see
http://www.gly.uga.edu/schroeder/geol3010/3010lecture06.html
http://www.rockhounds.com/rockshop/xtal/part7.html
http://www.stanford.edu/group/glam/xlab/MatSci162_172/LectureNotes/02_Geometry,%20RecLattice.pdf
Cheers, Uwe
*********************************************
Priv.-Doz. Dr. Uwe Kolitsch
Institut f�r Mineralogie und Kristallographie
Geozentrum, Universit�t Wien
Althanstr. 14
A-1090 Wien
Austria
Search the Mineralogy Database
Example Subject Searches
Example: forms 0-01 finds all minerals
that have the 001 face.
note-forms are only applicable to minerals with java crystal forms
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