Eagle Hawk Claim Field Trip Report
LEADER: Ray Horton
DATE & TIME: Saturday, August 4th.
ATTENDEES: The Nelsons, Bob Loeffler, Ron and Judy Knoshuag, Andy Taylor, Rob DeBus, Eldon Hunewell, Moyra Lyne, George Franzen, Richard Parsons, Mary Ellen Kennedy, Don Heiden, and the Kunzes, Knights, Larsens and Mullens. Perhaps a few more that I am not acquainted with.
The group met at 9 A.M. at The Forks Cafe at Livermore. We left several vehicles there as there was limited parking at the collecting area. We proceeded west past Red Feather Lakes, made a stop at a National Forest Campground, and arrived at the site at about 11:30. A moderately vigorous hike was required to reach the area where diamonds could be found. I (Andy) got separated from the group as there was a dense lodgepole forest covering the mountain. After wandering round for about an hour, I finally found Ray and about half of the group (the rest of the group were still wandering!). They were digging and screening for diamonds. I sat down, ate my lunch and watched the diggers (work attracts me! I could watch it all day!). No diamond nor any kimberlite (the host rock that carries diamonds) were found. There was a "dike" on a map which Ray had shown us and I thought that I had located it during my feverish wanderings earlier in the day. There were fragments of rock composed of greenish yellow epidote (epidote is a secondary alteration mineral) and pieces of pegmatite containing quartz and feldspar scattered around the presumed dike site. I mentioned this to Ray and so the group trudged off up the hill in search of it. We relocated to this area and began looking around. I finally found a highly weathered chunk of kimberlite, about the size of a grapefruit, lying on the ground. Some digging and screening revealed several more pieces of kimberlite. Alas, no diamonds were found by screening, but we did prove that the dike contained kimberlite and presumably diamonds. It is very difficult to find diamonds. Kimberlite in the diamond mines of the world will only contain 1 to 4 carats of diamonds per ton (a nickel weighs 5 carats!). One probably would have to screen several yards of soil in the area of kimberlite to have a decent chance of finding a diamond!
The kimberlite we found was, as I said, highly weathered, but one could still see the decomposition zonation of the olivine grains in it. As the kimberlite magma rises up to the surface, the olivine decomposes to serpentine, which is what kimberlite is composed of. None of the indicator minerals (grains of red pyrope garnet, chrome diopside and others) were found, with the exception of a few flakes of bronze-colored phlogopite (a mica) which was in the weathered samples of kimberlite.
In summary, no diamonds were found but we did find some pieces of kimberlite, had a nice hike with good weather and had a good time. Thanks to Ray Horton for leading the trip and taking us into a restricted mining claim.