CompuServe Messages

Hi, folks– I just got back from Crater of Diamonds State Park in Arkansas. This is a kimberlite/lamproite pipe, which produces a modest number of diamonds, as well as occasional garnets and peridots. Owned by the state, it is not mined commercially, being instead open for the public to try their hands at diamond mining. I am fuzzy on whether kimberlite/lamproite pipes are intrusive or extrusive igneous rocks; the pipe formation suggests to me they are an extrusion, suggesting to me there may have been a volcano on that site long since worn away – the "diamond mine" is not especially higher than its surroundings. The "diamond mine" part of the park ($4 admission to that area) is turned over by heavy equipment monthly – it looks sort of like a newly-plowed field. I found numerous chunks of kimberlite (or lamproite? I do not know how to distinguish them), and that is all I came away with; my companions also left with no diamonds, though they saw another woman having 5 diamonds verified. Having no diamonds to show, and seeing no reason why fishermen should have a monopoly on "fish stories", I would like everyone to know that I did find a golfball-sized fluorescent diamond crystal in kimberlite, but there it was not fluorescent and there were so many peridots and garnets cluttering up the specimen as to limit its aesthetic quality as a specimen and leave it useless for anything but faceting, so I threw it back for some lapidarist to find. –Doug