This location is the best, no doubt in my mind, of the quartz type geodes. The shells of the geodes from this location, have more calcite included in the quartz. This makes them 'soft', not brittle, and I can easily break these into two perfect halves with a hammer. The secondary minerals, crystallized within the hollows, run the whole Keokuk geode mineral list.
All the different types and colors of chalcedony are found here, usually sprinkled with pyrite cubes or marcasite 'antennas'.
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Aragonite is found here with its white crystallized 'balls' in all forms of deterioration to calcite paramorphs.
Dolomite is endemic to the Crystal Glen geodes and its saddle shaped crystals are displayed in many shades of yellow, pink, and red, depending on how much iron they had absorbed. Some of the dolomite is clear or opaque showing very little iron absorption. When these dolomite 'saddles' are sprinkled or run through with pyrite or marcasite crystals, they are a wonder to behold.
Pyrolusite is common here in its dendritic form, sometimes crystallizing on, or in, a calcite crystal for better display.
Selenite is found here, and looking carefully with a 10x loop is sometimes rewarded with with a nice cluster of clear needles.
Sphalerite crystals are here in small 'flakes' or complex crystals, never very big, and always associated with kaolinite and the most sought after mineral at Crystal Glen, blue barite. Though always small, caused by kaolinite absorption, the little blue barite crystal clusters are very aesthetic. The soft blue against gemmy quartz, yellow dolomite and silky calcite, make for a pretty display from Mother Nature.
Jarosite can be found here in its hard to find crystallized form, coating calcite crystals or dusting a mineralized pocket.
This last picture displays a nice two inch long capillary pyrite crystal, and this type of crystallization is occasionally found at Crystal Glen, along with the more common cube and filiform types. The hollow geodes from here are consistently pretty, and even the ones without a secondary, are gemmy quartz that would delight any old kid.
As you can tell I really like the Crystal Glen geodes... but there is a problem, as the area, encompassing three different landowners, is No Trespassing. The claim jumpers are so bad here, the landowners formed a neighborhood watch to help each other stop this madness. Although their hearts were hardened, they all were nice to me when I asked for permission. I explained to them why they were being harassed, but the little blue barite crystal geode I showed them did nothing for these nice landowners, whose only experience with rocks was to throw them out of their corn field... with a curse. The landowner thought I, and all my kind, must be crazy to care so much about a little round rock with a teeny blue blob. He seemed almost disappointed that all the trouble he was getting from trespassers was over something so insignificant. But... I begged and pleaded for these folks to keep an open mind, and a few weeks ago I got the call. One of the landowners might be willing to open up his land for Geode Fest 2013. It is still in the works, but very possibly the upper Crystal Glen snowball locality will be opened up for the masses in late September. I have a nice snowball from this location that I put on my house as the geodes are usually disc-shaped and fit nicely with the flat rock veneer.
The upper Crystal Glen (east of the highway bridge) has several geode exposures in the banks and the bed of this wild little creek. This part of the creek doesn’t get the trespassing pressure the lower part gets, as it is quite a jungle and has no road running along its side. The passages in the Keokuk bible concentrates more on the lower creek exposures (just as I did above) and barely mentions the upper part (only to say there are snowballs somewhere up there with a little x). On the first of September 2013, Mike (geode festival organizer) and I explored this little creek with the landowner. Way up the creek, hidden in the bed under the shallow water, was the disc shaped geodes containing the snowballs. Stretching for 100 yards in the bed of the creek, the vein was easily spotted as the landowner has not given permission for several decades and the geodes were visibly sticking out. In order to dig on this vein, the creek needs to be dry. If there is flowing water, the exposure would be under water and hard to exploit. This has been a summer of historical drought (no measurable rain for the entire month of August) so even though the landowners corn crop has been significantly reduced and his soybeans are toast, its good for the geode hunter. Hopefully, at Geode fest 2013 this September, anyone who wants to, can have a decent chance to find a fabulous Keokuk snowball geode.
See you at Geode Fest!