GOETHITE
Specimen goe-8
$ 38.00Dims: 4.0" x 3.5" x 2.7" (10.2 x 8.9 x 6.9 cm)
Wt: 12.9 oz. (365 g)
Chihuahua, Mexico
This particular Goethite specimen is unusually heavy for its size. This is because there is a considerable amount of crystalline selenite attached to it. The Goethite takes on a few different forms. One of these is the botryoidal form that Goethite often takes on, though there is only a small amount of this. When in this form, it coloration ranges from metallic gray to black to the red-brown of limonite, and its luster ranges from metallic to black. Some of the material is massive and shapeless, and generally retains a red-brown coloration. Much of the massive material, however, has taken on the role as an epimorph, creating a "mold" of sorts. This occurred when there were large selenite crystals present, before the Goethite formed. The Goethite filled in the spaces around the selenite crystals, which were subsequently worn away by running water. This left the Goethite with a form shaped by the "negative space" of the missing selenite. I think these types of specimens are particularly interesting.