Positive and negative tetrahedrons

“If a positive and negative tetrahedron occured together with equal development, the resulting crystal could not be distinguished from an octahedron, unless, as is usually the case, the faces of the two forms showed different lusters, etchings, or striations that would serve to differentiate them.” — Ford, 1912

Keywords

geology, geometry, negative, tetrahedron, positive

Galleries

Pyramids

Source

William E. Ford Dana's Manual of Mineralogy (New York: John Wiley and Sons, Inc, 1912) 28

Downloads

TIFF (full resolution)

2400×2052, 240.5 KiB

Large GIF

1024×875, 34.9 KiB

Medium GIF

640×547, 19.7 KiB

Small GIF

320×273, 9.2 KiB