Mottramite

It's advisable to handle mottramite carefully to avoid generating dust and wash hands thoroughly afterward. When cutting or polishing mottramite, wear a dust mask to prevent inhaling heavy metal particles. Store mottramite in a sealed container in a well-ventilated area, away from children and pets. For those involved in crystal healing, never put it in your mouth.

No cleavage has been observed. The mineral is brittle and breaks with a subconchoidal to uneven fracture. It is quite soft, with Mohs hardness 3 to ​3 ⁄2, just a little harder than calcite. The hardness is slightly greater on crystal surfaces. It is a heavy mineral, with specific gravity 5.9, because of the lead content. It is readily soluble in acids.

Drusy crusts of tiny intergrown crystals are common, also encrustations and mammillary or botryoidal surfaces. The crystals are equant dipyramids or prisms parallel to the c crystal axis, but always microscopic. The colour is various shades of green, yellow-green, blackish brown or nearly black. Crystals often grow step by step, with the different steps or zones having different colours. The streak is yellowish green, or yellow, and the crystals are transparent to opaque, with a greasy lustre.

The type locality is Mottram St Andrew, Cheshire, England, UK and type material is conserved at the Natural History Museum, London 52314-52315. Mottramite is a secondary, supergene mineral found principally in the oxidized zones of vanadium bearing base metal deposits, especially sandstones. Associated minerals are descloizite, duftite, mimetite, wulfenite, cerussite, azurite and dioptase.

Mottramite forms in the oxidized portions of copper-lead deposits, making it an occasional ore for lead and copper. Both metals are essential for a wide variety of industries and applications, which makes mottramite valuable. This mineral is also occasionally cut into gemstones and sought after for mineral collections.