New Mexico Geological Society Annual Spring Meeting — Abstracts

Basic geometric forms such as cubes, octahedra, rhombohedra, and tetrahedra may be made by folding flat paper or envelopes, both reasonably priced starting materials. These may be used to help visualize solid forms in crystallography and mineralogy and numbers of them may be used to create unit cells. Tetrahedra in particular are easy to make by folding and cutting small envelopes. Tetrahedra may be linked to build silicate and carbonate crystal models.

A ring of six tetrahedra may be linked along two sides of each to form a hexaflexagon. Spillhaus and the GeoLearning Corporation (Sheridan, Wyoming) have produced hexaflexagons with illustrated geographic, geologic, and astronomic themes on each side printed on stiff paper (Spillhaus copywrite, 1985). These models are also reasonably priced and require assembly. As an alternative, we have combined the rapid production of tetrahedra from envelopes with various geological themes printed in color on hexagons to produce customized hexaflexagons covering the topics of earthquakes, plate tectonics, and geology of New Mexico.

Illustrations showing how to make a tetrahedron and hexagonal illustrations that can be printed and mounted on the sides of hexaflexagons are available at the New Mexico Bureau of Mines & Mineral Resources earthquake education Web site (http://tremor.nmt.edul). The files are currently available as downloadable and printable .gif files, and may be available as higher resolution .pdf files in the near future.