Lapidaryforum.net
Let's Rock => Rockhounding Tips, Maps, Trips Etc. => Topic started by: Itsandbits on June 30, 2015, 08:02:59 AM
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I dragged my daughter who was visiting from the not so wet coast and a rockhounding buddy up to an old limestone mine that was shut down 30 years ago. Along with the limestone, massive white quartz deposites were exploited to make crushed white driveway stone, decorative border material and the crushed white quartz that used to be plastered on the outside of many houses. While mining this material, clear terminated quartz crystals up to 2ft. were reported to have been found. We spent the day getting to and digging through the waste piles in the hopes of finding something of interest. Fighting off the hordes of black flies and well over 100 degree day on a glaring white wasteland was no fun but we persevered and found a few small crystals. This is my largest; pretty tiny but I'm going back on a cooler day to try again. Frank, you suggested that if the crystal was a bit cloudy, I might look for star qualities, I've tried looking directly at the point with the sun over my shoulder but nothing, should I grind the point round and try again?
(https://lh6.googleusercontent.com/-ffIxqKJwoAM/VZKmcTRPo5I/AAAAAAAAUrc/m2FcJbTHhwo/w980-h735-no/15%2B-%2B1)
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The cloudiness would be evident in regular reflected light if it were there. These large quartz deposits sometimes host a real surprise. Feldspar veins may exist near the margins of the deposit. If the quartz has been worked back to the country rock you may find feldspar veins a few inches thick. They are often between the quartz and the country rock. They are usually almost water clear and could pass for non terminated vein quartz. This is the type of feldspar can can be top quality moon stone. At a site in Montana the feldspar was dozens of feet thick and was superb quality moonstone. The owner got greedy and blasted the entire deposit in one giant blast destroying the value of the feldspar in the process as it fractured it by developing the cleavage planes. A deposit worth millions was then only suitable for fill. I recently found a good feldspar vein of this type a few hours from me. When I can walk I will check it out.