Bighorn & Pryor Mt Range, Montana (near Wyoming border)
| Originally inhabited by Crow Native Americans,
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. Around 1900s, the cattle were used to be driven through Dryhead
Canyon toward Balintine, Montana. The ownership of the canyon had changed
several times over the century. During the 1970s, it was opened as a fee-collecting
site for anyone to try their luck at digging for the agates there and there
had been an attempt at commerical mining there. But now, it was closed
to any collecting even the owner was said to have done some harvesting
of the deposit once in a while.
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. 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. Sometimes, the arrowheads crafted from the agates had been found.
The Bear Canyon along the Pryor Mountain produced the black and white agates, but it seems that very little of that agate is available.
|With an amethyst geode|
|Rare yellow color||Rare "Waterline" Quartz with agate in the center.
Shows that the nodule was not fully filled when
quartz and agate were growing.
can see some Dryhead Agates for Sale at the Online Agate & Thunderegg