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 #4156 4080 X 6144 pixels (8.03 MB)
Macro photograph of the silvery blue bladed structure of the mineral kyanite, an aluminum silicate. From Brazil Image #2584 4748 X 3117 pixels
Macro photograph of the crystalline structure of citrine, a variety of quartz; the coloration comes from tiny particles of iron oxide suspended within Image #3698 4800 X 3200 pixels (5.42 MB)
