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Post by kk on Feb 5, 2012 0:57:58 GMT -5
Got this Polkadot last year. Bought several pieces (fragments mostly) and none of them contained the traditional "Dot's". Hard as hell, but easily falls apart with my way of cutting. Takes very well to grinding though. Here is the rough and the preform (sorry, had only I-Phone yesterday) Final cut And here is my question: there are some silvery metallic inclusions all over this piece, yet they can only be seen at very shallow angles in the glare of light. Nothing special as such, but there is not a hint of undercutting (something that I was told happens nearly every time those inclusions turn up, and should certainly happen in a mix with such hard material). So what could those inclusions be and why is there no undercutting? Thanks in advance for any suggestions to clear up (to me) this mystery....
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Post by frane on Feb 5, 2012 9:33:34 GMT -5
I am not so sure that is polkadot. I have never seen it with that clear agate. All that I have, with patterns, etc are all a solid white or simi transparent. Almost looks like a Texas or Mexican moss the way it has those rippled streamers in there. Of course, that could be loosly related to roostertail and that is Utah isn't it? The metallic material could be anything from marcasite, pyrite to Mica. They can all undercut or pit because they can be a bit softer than the agate. No matter what it is, I is a great shape and a beautiful cab! Fran
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Post by FrogAndBearCreations on Feb 5, 2012 9:36:36 GMT -5
cool stone and cab!
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,472
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Post by Sabre52 on Feb 5, 2012 9:53:03 GMT -5
I'm with Fran, looks more like a moss/plume agate type to me. certainly not like the Oregon material usually sold as polka dot agate. The inclusions in that sort of agate, if metallic, are most often marcasite or specular hematite both of which will often polish up quite well if imbedded in chalcedony. Blacker metallic inclusions of magnetite or manganese sometimes tend to be dustier and undercut badly unless well impregnated with silica......Mel
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Post by Donnie's Rocky Treasures on Feb 5, 2012 9:53:20 GMT -5
That is a beautiful piece!
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SteveHolmes
fully equipped rock polisher
Member since July 2009
Posts: 1,900
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Post by SteveHolmes on Feb 5, 2012 11:33:09 GMT -5
Awesome Cab! Love hearing all the opinions....it's like I'm taking a free geology course. Thanks Fran and Mel. steve
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unclestu
Cave Dweller
WINNER OF THE FIRST RTH KILLER CAB CONTEST UNCLESTU'S AGUA NUEVA AGATE
Member since April 2011
Posts: 2,298
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Post by unclestu on Feb 5, 2012 15:39:52 GMT -5
I love that shape very unique and that stone has one heck of a nice look to it Stu
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Post by Toad on Feb 5, 2012 16:18:53 GMT -5
Great looking cab.
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Post by Bikerrandy on Feb 5, 2012 19:37:05 GMT -5
I do in fact have some polka dot agate exactly like that, one half is clear with moss but the other have looks like the traditional blue-white with polka dots. It takes a mean shine.
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Post by kk on Feb 5, 2012 20:22:18 GMT -5
Thanks everyone for the likes and the great information, Shape is just an experiment to include two inverted curves and came into being as I got frustrated with someone (somewhere else not here on the forum) commenting and praising on how difficult it is to produce a perfect "Round" cab. The cab shown deserved respect, as it was basically "Perfect", but it was also perfectly "BORING" (singular translucent color). Mind you, I like and respect both, the work shown and the one commenting. But when you have so many things to choose from, even a perfectly worked round becomes insignificant, if there is no other criteria to judge by. Here on my own cab; What stumped me more than anything was the missing undercutting of the silvery inclusion, but I guess Mel must be right with the encasing solution. The metallic look only came with the cutting, I'm nearly 100% sure it was not there before. So it is encased within the plumes. I just got up (Monday morning) and wanted to accept that my supplier gave me the wrong name for this stone,..... then comes Randy, ...... and now I'm back to square one..... LOLOL Great way to start the day with a continuing puzzle, ...... Thanks, Kurt
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