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Dryhead Agates Bighorn & Pryor Mt Range, Montana (near Wyoming border) |
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The Dryhead Agates were named after
many bison skulls found near the site. That was where the Native Americans
were said to run the bisons over the cliff, killing many of them, and then
arranging the bison skulls in ceremonial manner. The agates come in form
of concretion nodules found in the dark colored shales, and because of
overlaying limestone formations, it takes some hard digging to obtain the
nodules and only a small percentage of the nodules were said to be of any
good. It used to be a fee collecting site in 1970s, and there had been
changes in the ownership of the site and some mining activities using the
heavy machines.Currently, it appears that the owners of the area is not
interested in allowing anyone to dig for the agates.
The typical color of the Dryhead agates are brownish orange but they can also come in the yellow, red, pink, gray, lavendar and white colors. The color combo of orange, red, pink and white is most desirable. It's very common for the Dryhead agates to contain interlaying of quartz and agate which seem to support a concept that the agates may have been formed by successive layering following the wet and dry seasons.. The Dryhead agates have an interesting form of fluorescence. The quartz bands of the orange Dryhead agates (without pink/white cores) strongly fluoresce green, hence, the glowing neon green "contour lines" against dark non fluorescing bands under ultraviolet light. |
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Minor shadowing effect |
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