Limonite is extremely common and forms the coloring matter in many soils. It is also responsible for the coloring on the weathered surfaces of rocks. Much Limonite, especially the fibrous type, is either Goethite or altered Goethite that absorbed water in its chemical structure.

The famous Ojuela Mine in Mapimi, Durango is one of the most prolific Hemimorphite localites, forming well-shaped crystals on a Limonite matrix. Very large white crystals and fans have been found at Santa Eulalia, Chihuahua; and toothpaste-blue botryoidal Hemimorphite has come from the Santo Niño Mine, Santa María del Oro, Durango.

Adamite crystals are usually embedded in rusting, crumbly, brown Limonite matrix that stain the hands. Since the Limonite crumbles when scrubbed, care must be exercised when washing such specimens. Since the Limonite crumbles when scrubbed, care must be exercised when washing such specimens.

Limonite, an amorphous mineral, is commonly found in rhombohedral crystals, as it frequently pseudomorphs after Siderite. Concretionary Siderite nodule s are noted for containing a wide variety of flora and fauna fossils, especially in the open-pit coal mining operations of eastern Illinois and western Indiana, where these concretion s are ...

Three intergrown Limonite pseudomorphs after cubic Pyrite crystals up to 17 mm. The original surface striations of the original Pyrite are still visible. Limonite frequently forms pseudomorphs after Pyrite, preserving its original shape. Locality: Porter, Stanly County, North Carolina: Dimensions: 26 x 18 x 16 mm. Specimen Grade: A: Photograph

Limonite pseudomorphs after Pyrite from Porter, Stanly County, North Carolina

Goethite is a common mineral, and is a frequent matrix material for other more aesthetic minerals. It is usually a dark, uninteresting mineral, though specimens from a handful of locations (especially Colorado) are remarkable for their delicate and beautiful crystal growths and velvety botryoidal growths.

Earthy brown Limonite pseudomorphs after scalenohedral Calcite crystals up to 12 mm long with thin coating of brown Jarosite on some surfaces. Locality Silver Hill Mine, Pima County, Arizona

Limonite pseudomorphs after Marcasite from Potosi, Washington County, Missouri

Jarosite's crystal forms combined with its color easily identify it. However, poorly crystallized examples and massive forms of Jarosite may be difficult to distinguish from other minerals, such as Limonite. Jarosite is also indistinguishable from its isomorphous mineral Natrojarosite by ordinary methods.