Hi I have a green garnet. The person said it was green garnet they found off their property in northern California. I got it from etsy. The rock is dark green. I was tapping on it and a piece of the rock that had rust in-between came off pretty easily. I know this is opaque so far but do you think this is a ts
Green garnets from California? That’s a new one on me.
It shipped out of northern EUREKA CA. I did google it and green garnet did come from this locaction!
I mean that it came from northern ca location is what I googled.
This igs website also said " Where are Grossulars Found?
Numerous localities produce gem-quality grossulars around the world. Some notable sources include
I think this is green serpitine after all. thank you!
*whew
there are 4 ophiolites of Jurassic age extending from northern California into southern Oregon… The Josephine ophiolite forms part of the Klamath Mountains in southern Oregon… ophiolites are obducted oceanic crust… pieces of the crust broke off and were thrust up rather than being pulled own in the subduction zone that made the Sierras and later the Cascades… Ophiolites are mostly serpentinite rocks, metamorphosed hydrated basalts and deeper ultramafic serpentinized peridotites…as such, some of them contain garnets, including andradite. Grossular garnet has been reported but calcium garnets are not as common and iron and magnesian garnets…garnets are not a common constituent of serpentinites…serpentine is green to black due to the high Fe and Mg content…chromium in the form of chromite was discovered in mineable quantities in the Klamath range but not enough to be economical and far too environmentally destructive to mine… Chromium garnets are quite possible in this kind of rock…but not likely in gem quality…Blueschist metamorphic facies (low temperature, high pressure) rocks are also present in a belt going from northern California into the Klamath mountains… low temperature, high pressure metamorphism is the source of nephrite jade in California, Alaska and Wyoming…
Thank you. I wonder what If I will find something neat!
obducted slabs are high pressure metamorphic rocks… basalt turns into eclogite… the plagioclase feldspar gets transformed into a garnet phase at a depth of 70 km…eclogites will have garnets in them, but high calcium garnets aren’t common compared to Fe garnets… some basalts will have higher calcium contents so you might find your grossular garnets… also green gemmy omphacite, a high pressure clinopyroxene with a composition ranging from diopside which is calcium and magnesium, to jadeite, which is sodium aluminum… find where the eclogite is and look there… it will be on top of the peridotite deep layer, although the slab may be turned upside down or more likely sideways… I don’t know enough about the regional geology of northern California and the Klamath mountains to tell you exactly where to look… but you should be able to find it on a geologic map… just remember that all of the rocks have been serpentinized, so distinguishing rock layers might be difficult. Green coloration comes mostly from iron, but there is chromium also… chromite is present…
Happy rock hunting…hope you find the mother lode…
Hardness?
Question: does the rock you received match exactly with the eBay pictures online?
I am unsureof the hardness. I think i see to an extent some orange and white colors in it! I see lots of green. Im not sure whitch part to try to do the hardess test on. I did get what was from the picture from etsy. It was sold to me as a green garnet though. i got it from the shop called eyesofthenepetite on etsy. They sent me a coupon before i bought it. I took pictures of only a piece of the rock. The rock is somewhat bigger that this actually.
your best bet on identifying your speciment is to take it to a geologist at a local university. You will need to tell the the exact place that you found it… the area in general that you found it is very complex geologically. Type location is critical. Good luck and Merry Christmas!!!
