CAMPYLITE (=Mimetite) WITH PLATTNERITE (MINIATURE), Cornwall, UK

Campylite is a type of the lead arsenate mineral called mimetite. It got its name from the Greek word 'kampylos', which means bent, because its crystals are shaped like a barrel. Sometimes, people also use the name campylite to refer to pyromorphite.

This mineral is found in the upper lead deposits that form when galena or cerussite oxidize. The biggest places where campylite is found are Příbram in Bohemia and Dry Gill, Caldbeck Fells, which is close to Wigton in Cumbria, England.

Plattnerite is a type of oxide mineral and is the beta crystalline version of lead dioxide (β-PbO2), with scrutinyite being the alpha form. It was first discovered in 1845 and named after the German mineralogist Karl Friedrich Plattner. Plattnerite appears as bundles of dark, needle-like crystals on different minerals; these crystals are hard, brittle, and have a tetragonal shape.

Occurrence
Plattnerite can be found in many dry places in North America (including the US and Mexico), most parts of Europe, Asia (like Iran and Russia), Africa (specifically Namibia), and Southern and Western Australia. This specimen is from Cubria, UK and counts as a very rare find. It is found in weathered hydrothermal base-metal deposits as hay-like bundles of dark prismatic crystals that are a few millimeters long; these bundles can grow on or sometimes inside various minerals, such as cerussite, smithsonite, hemimorphite, leadhillite, hydrozincite, rosasite, aurichalcite, murdochite, limonite, pyromorphite, wulfenite, calcite, and quartz.