ROSASITE
Specimen ros-13
$ 25.00Dims: 3.01x2.14x1.33" (7.65x5.45x3.37cm)
Wt: 4.08oz (115.8g)
Omega Mine, Helvetia District, Arizona, USA
A piece of limonite is host to hundreds of tiny turquoise colored balls of rosasite. A loupe reveals these as clusters of still tinier balls of rosasite. They are solid, and do not appear to be composed of acicular crystals. The bulk of the visible crystals on this specimen are transparent, and milky to colorless, as flat blades with a rounded face. They are intergrown like some barite or selenite clusters, but I believe that they are something else, such as calcite or hemimorphite in a form I haven't seen before (both of these are commonly associated with rosasite), or possibly they are hydrozincite, which is chemically quite close to rosasite in composition.