This high quality flat brings together particularly attractive specimens with Philipsbornite and Osarizawaite crystals from the legendary Grandview Mine. The specimens display intense yellow, yellow green, and turquoise colors, commonly as dense crusts or fine grained aggregates, locally with clearly developed crystalline areas. Individual crystals can be locally recognized, but most occur as tightly intergrown coatings, which is characteristic for this mineral assemblage. The diversity of textures, color variations, and associated minerals makes this flat an especially expressive representation of this classic locality.
Geology & Origin
The Grandview Mine is one of the world’s most important localities for secondary copper and lead arsenates. Philipsbornite and Osarizawaite form here in the oxidation zone of copper rich ore veins under strongly oxidizing conditions. Variations in chemical environments and complex paragenetic processes result in a wide range of colors and aggregate forms, which are impressively illustrated by this flat