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can you identify this stone?

0 votes

hi guys, great community. i'm trying to identify these stone plugs - any guesses? alt text

thanks in advance!

asked Mar 24, 2013 by lishd (400 points)

14 Answers

0 votes

Definitely looks like some sort of chalcedony/agate. It looks like moss agate only difference is the color which is not green but red. Test its hardness and if it is around 7 you'll be able to determine that its indeed chalcedony/agate.

answered Mar 28, 2013 by hershel (46,460 points)
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thanks hershel. the best i could guess was an agate too, but i had a few lapidaries guessing red coprolite. it was originally sold as "carnelian agate", but that didn't seem right at ALL. i still can't find any example photos of chalcedony or agate that have the same sort of cloudy red areas, though.

i have some quartz rough which definitely will scratch it, but it feels like obsidian would, too. steel definitely didn't. i'm loath to actually leave a mark on the plugs, but at this point i'd guess the mohs is 5-6...

answered Mar 28, 2013 by lishd (400 points)
0 votes

Well, carnelian is a red agate or chalecedony, so although I would not classify this as carnelian since there are other colors here too, I can see why the dealer would label it as carnelian.

I have never seen an agate or chalcedony with this particular pattern, but that's definitely what it looks like. However, chalcedony will give you the hardness of a solid 7 - or maybe half a point lower to 6.5 with impurities, so if you are reading lower values then that is strange. Can you test it with a piece of feldspar (hardness of 6)? It should not scratch if it is indeed chalcedony/agate.

answered Mar 28, 2013 by hershel (46,460 points)
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okay, my desire to identify this stuff is greater than my desire to have no scratches on it. i don't have any feldspar around, but i do have a bunch of titanium, which is a 6... & they both scratched each other equally. so i'm sticking to 6.

answered Mar 29, 2013 by lishd (400 points)
0 votes

Where do you have natural titanium from? Are you sure what you are using to scratch is a 6? If so, it is not a quartz material but softer material. I would be very surprised if it wasn't a form of quartz.

answered Mar 31, 2013 by hershel (46,460 points)
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OH! thank you, that's totally my mistake - i read "titanium" & didn't even think that body jewelry-grade titanium, ASTM f-136, is 6Al4V. sorry, i've never had to test stones in this way before - i've always been able to identify them by sight since the range of stones typically made into body jewelry is fairly small.

i can't seem to find a mos score for Ti6Al4V specifically. too bad i don't have any niobium, as body jewelry Nb is pure (99.9% at minimum). i tested again with the natural obsidian, & left more of a mark on the obsidian than on the mystery stone - but i did get a TINY mark on the latter, which still says maybe 5 or 5.5 with impurities...

any other ideas?

answered Mar 31, 2013 by lishd (400 points)
0 votes

It reminds me a little of a Mexican Flame Jasper, except for how much gray there is in your stone.

answered Apr 1, 2013 by purlofgreatprice (220 points)
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you guys sure you don't think it's coprolite? http://www.ebay.com/itm/zbv-Fantastic-Coprolite-Rough-Slab-/370621541120

looks awfully similar...

answered Apr 4, 2013 by lishd (400 points)
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I'm sorry, I can't help it--dinosaur dung?? LOL Maybe the poor critter had hemorrhoids (hence the red).

answered Apr 4, 2013 by purlofgreatprice (220 points)
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OK, my bad. Could be coprolite :) Obviously I'm kind of new at stone identification.

answered Apr 4, 2013 by purlofgreatprice (220 points)

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