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The Spring 2011 issue of The Earth Scientist is focused on modernizing seismology education. Thanks to IRIS, you can download this issue for free as a pdf. Print copies are available in our online store.

Shapes of Mineral Crystals

Cubic crystals are not always cube shaped! There are many that are shaped like octahedrons (eight faces), and some that are shaped like dodecahedrons (12 faces).
Tetragonal crystals are shaped like cubic crystals but are longer in one direction making shapes like double pyramids and prisms.
Orthorhombic crystals are often shaped like rhombic prisms or dipyramids (two pyramids stuck together). They often look a bit like tetragonal crystals except that they are not square in cross section (when you look at the crystal on end).
Hexagonal crystals often look like six-sided prisms. When you look at the crystal on end, it looks like a hexagon shape in cross section.
Monoclinic crystals look like tetragonal crystals that have been skewed. Often, they form prism shapes and double pyramids.
Triclinic crystals are sometimes very strange shapes! They are usually not symmetrical from one side to the other.

All images are Windows to the Universe Originals
Last modified July 17, 2007 by Lisa Gardiner.

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The Fall 2010 issue of The Earth Scientist, focuses on rocks and minerals, including articles on minerals and mining, the use of minerals in society, and rare earth minerals, and includes 3 posters!

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