Goethite

Goethite pseudomorph after gypsum

Origin: La Negra, Mun. de Carmargo, Chihuahua, Mexico

Ex. Marilyn Dodge collection

Sample size: 3.9 x 1.9 x 1.9 cm

Goethite pseudomorph after pyrite

Origin: Pelican Point, Utah Co., Utah, U.S.A.

Ex. Richard Hauck collection

Sample size: 4.3 x 4.0 x 3.8 cm

Origin: Florissant, Teller Co., Colorado, U.S.A.

Ex. Smale collection

Sample size: 5.2 x 4.0 x 3.7 cm

Goethite pseudomorph after gypsum. The large crystal measures 2 cm, and is hollow in the center - really, just a delicate shell - probably the gypsum was dissolved out of the interior after the geothite was deposited on its surface, leaving this as a "cast."

Origin: Nevada, U.S.A.

Sample size: 7.6 x 4.2 x 3.0 cm