LIMONITE
Specimen lim-3

Dims: 3.2 x 1.6 x 1.5" (8.1 x 4.2 x 3.9 cm)

Wt: 4.1 oz. (117 g)

Washington County, Missouri, U.S.A.

A few dozen dull, dark brown Limonite crystals coat the siliceous base of this hand specimen. They are in very good condition, showing little damage, and reach lenghts of nearly 0.4" (1 cm). As the crystals pseudomorphed from marcasite, they have retained the orthorhombic form and "coxcomb" habit of that mineral- most of the "coxcombs" are quite well-defined. The Limonites appear to rest on a thin crust of slightly drusy agate.

Dims: 1.0 x 1.0 x 0.8" (2.5 x 2.4 x 2.0 cm)

Wt: 0.5 oz. (15 g)

Boulogne, France

This large thumbnail piece consists of a cluster of Limonite crystals that were pseudomorphed from marcasite. They are in excellent condition and reach lengths of up to 0.5" (1.2 cm). All have retained the excellent orthorhombic bladed form of the marcasite, but have a dull, rust-brown coloration and a dull waxy to matte luster. Also, the cluster is less dense than it would be were the crystals still composed of marcasite. There is no host rock present, and the piece is affixed inside a plastic thumbnail box.

Dims: 2.65x1.79x1.46" (6.74x4.55x3.71cm)

Wt: 4.06oz (114.8g)

Pomarolli Mine, Divino das Laranjeiras, Minas erais, Brazil

This limonite "crystal" is a pseudomorph after siderite, and is accompanied by a large number of mica books, probably biotite. The limonite is opaque and a mottled brown in color, with a surprizingly good luster. The mica is brown and transparent in very thin sections (showing brown highlights).