Macrophotograph of a small portion of a Cactus quartz (a.k.a. Spirit quartz) crystal cluster with purple amethyst. The orange coloration is due to iron oxidation and small iron inclusions can be seen in the matrix of many of the crystals. From the Magaliesberg Mountains of South Africa. Imge #4116 6144 X 4040 pixels
Macro photograph of a sliced and polished piece of Rolling Hills dolomite; Chihuahua, Mexico Image #3678 6144 X 4080 pixels
Theodore Roosevelt National Park; North Dakota Image #3815 4080 X 6144 pixels
