I had to make a quick shopping run this morning. My Jeep got ducked!
https://www.susans.org/index.php?topic=246523.msg2318007#msg2318007I have cleaned up the four rocks that I brought back from my neighbor's property. One was granite, and the other three appear to be gabbro with olivine intrusions. Gemstone quality olivine is called Peridot. Since these are tiny crystals within the gabbro rock, I'll toss them into the rock tumbler and see how they look after polishing.
This find is significant from a prospecting viewpoint. The old-time gold prospectors felt that "greenstone" (olivine) was a sign that gold was nearby. "Greenstone" is not an actual stone, but refers to a variety of green stones. Olivine is primarily iron and magnesium. The higher the iron content, the darker the green. Lower iron content can cause the color to be more yellowish-green.
Since I found these stones in a creek bed, I want to hike upstream to see if I can locate the source. If I can find a nice outcrop of these rocks, I'll dig, dig, dig!
😁
