Almandine
These crystals of almandine, an iron-aluminum garnet, are euhedral (well formed) and show classic dodecahedral faces. The largest is about 1 cm across. This garnet is from Emerald Creek, Idaho, a once famous collecting site that sadly has deteriorated because so many people have collected there. Emerald Creek garnets are well know because when polished to produce cabochons, many of them exhibit asterism (a play of light that produces stars in the gem). Almandine has ideal formual Fe3Al2Si3O12.
University of North Dakota Mineralogy Collection, #1182
