Kidwellite is a mineral that belongs to the phosphate mineral group, specifically the wavellite group. It was first discovered in the late 19th century in Hamilton County, Ohio, and was named after William Truman Kidwell, an American mineralogist.
The chemical formula of kidwellite is Al12(PO4)11(OH)15·3H2O, showcasing the presence of aluminum, phosphorus, and hydroxyl ions, along with water molecules. Its crystal structure is typically found in botryoidal or globular formations, characterized by small, compact spheres with a smooth, rounded surface. These aggregates often exhibit hues of green or bluish-green, ranging from pale pastel tones to deeper shades.
In terms of physical properties, kidwellite is considered to have a low hardness (between 3 to 4 on the Mohs scale) and a relatively light density. It may also display a pearly or waxy luster when properly polished. Kidwellite is typically found in phosphate-rich environments, such as oxidized hydrothermal veins or phosphate nodules, and can be associated with other minerals like wavellite, lazulite, and crandallite.
Kidwellite is not widely used commercially, primarily due to its relatively small-scale occurrence and lack of economic viability. However, it is highly sought after by mineral collectors and enthusiasts for its unique crystal formations, vibrant colors, and association with other rare phosphate minerals. Its detailed study can also provide valuable insights into geological processes and the formation of phosphate-rich deposits.
