September Microphoto of the Month
This is a false color image of a garnet from an igneous rock in southeast Alaska. The image shows the distribution of the element calcium in the garnet crystal, with bright colors representing the highest concentration. When mineral compositions vary regularly in this way, the mineral is said to be chemically zoned. The zoning reflects changes in chemical and physical conditions during the growth of the garnet. The garnet in this image is about 5mm across.