Iron King Mine, Santa Maria District, Buckskin Mts, La Paz Co., Arizona, USA
Field of View: 3.9 mm
Hematite - the blue colour is as shot and is the result of an iridescent tarnish giving it a bright blue colour most noticeably on the edges. There are several spots in the image that show a deep red as the crystals are thin enough to transmit some light.
Doug Merson photo and collection.
Hematite is one of the most common minerals. The colour of most red and brown rock, such as sandstone, is caused by small amounts of Hematite. It is also responsible for the red colour of many minerals. Non-crystalline forms of Hematite may be transformations of the mineral Limonite that lost water, possibly due to heat.