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Post by Roller on Apr 3, 2011 20:31:24 GMT -5
I was trying to find some general info on snakeskin agate online and there doesnt seem to be much ... What causes the snakeskin like outside ? How is it formed ?> etc
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Post by Jack, lapidaryrough on Apr 3, 2011 21:21:45 GMT -5
Hydrated silicates, from being exposed to the elements, and its above the water table in acidic dirt. White skin Brazilian agate same. A lot of silica are white case from the same reaction. Petrified wood looks blonde - white.Western Oregon Material. when cut you`l see a Hydrated ring around it. Age kills
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,456
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Post by Sabre52 on Apr 3, 2011 22:06:11 GMT -5
Yep, that's how archeologists date obsidian artifacts too. It's called obsidian hydration dating. Older the glass is the more the exterior is impregnated by water so they examine a slice of the point or whatever and see how deep the hydrated crust is and the depth of the layer indicates how old the piece is. Chert paleo points I've collected in California's central valley have that same white crust you can see on the agate and pet wood mentioned above and obsidian points collected there often have a white patina that has fresh chips where more modern Amerinds found a paleo point and reworked it from a dart point into an arrowhead...Mel
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rockwizz
freely admits to licking rocks
Member since May 2007
Posts: 971
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Post by rockwizz on Apr 3, 2011 22:51:57 GMT -5
I learned something new today, thanks.
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