Macrophotograph of the structural detail in a pietersite gemstone from Arizona. Also known as 'Arizona tiger eye' it is a variety of chalcedony that contains amphibole mineral fibers that result in a chatoyant (optical reflectance) effect. Image #4155 4668 X 3200 pixels (7.53 MB)
Macro photograph of patterns in a slab of Josephines' Crown stone (a.k.a. awaruite); quartz based rock with pyrite from Grant's Pass, Oregon Image #3360 4800 X 3115 pixels
Macrophotograph of quartz crystals (Silicon dioxide) and pyrite (iron sulphide); from the Huanzala mine in Peru Image #3566 4800 X 3200 pixels
