This flat presents a diverse collection of Philipsbornite, Osarizawaite, Parnauite and Azurite crystals from the famous Grandview Mine in the Grand Canyon, Arizona, USA. The specimens display predominantly yellow green to greenish blue mineral coatings and crystalline aggregates on light brown to grey matrix. Several pieces show clearly recognizable crystal structures, partly as fine crusts and partly as small, well defined crystal groups. The strong color contrast between the secondary copper and lead minerals and the host rock gives the flat a vivid and visually rich overall appearance.
Geology & Origin
The Grandview Mine is a classic locality for secondary phosphate, arsenate and sulfate minerals formed by the weathering of primary copper and lead ores in oxidized zones. Philipsbornite, Osarizawaite, Parnauite and Azurite crystallize under arid conditions in fractures and cavities of the host rock, where complex geochemical processes lead to the precipitation of these rare mineral phases. The locality is regarded as one of the world’s most important sources for a wide variety of rare secondary minerals and is especially known for high quality micromount and small suite specimens.