rockstock
spending too much on rocks
Member since April 2019
Posts: 472
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Post by rockstock on Mar 4, 2020 20:59:11 GMT -5
For example, a petoskey stone or fossil that normally is in limestone or calcite form. When you find other versions that are different...are there many varieties or is it agatized, silicified, mineralized? Interchangeable?
Appreciate the insight or help!
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Post by Pat on Mar 4, 2020 22:03:59 GMT -5
I call such things “theme and variation”. Works in lots of situations. Not very scientific.
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Post by rmf on Mar 4, 2020 22:09:51 GMT -5
Mineralized would be a general term for any organic origin fossil that is either calcite or silica or even iron etc. I tend to think of silica replaced as anything that has SiO2 but not solid enough to cut and polish. That leaves agatized anything as good enough to cut and polish like p wood and dinobone, coprolite etc. Of course silicified would still apply to these as well.
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fuss
spending too much on rocks
Member since October 2018
Posts: 250
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Post by fuss on Mar 5, 2020 1:40:22 GMT -5
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rockstock
spending too much on rocks
Member since April 2019
Posts: 472
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Post by rockstock on Mar 5, 2020 7:06:54 GMT -5
Thank you for the tips
I have not been able to find a picture of an agatized petoskey stone, maybe my Google skills are lacking. I'll try to get some comparison pics later.
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Post by fernwood on Mar 5, 2020 8:11:37 GMT -5
Would love to see a photo of the stone you have. Agate Petoskey seems amazing.
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rockstock
spending too much on rocks
Member since April 2019
Posts: 472
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Post by rockstock on Mar 5, 2020 8:14:25 GMT -5
I have a couple, one is a larger rough(holes and crevices) but its agate like, mainly white. I have a small one that is white and yellow. Not great condition specimens but definitely cool and something to work with, cutting or tumbling to bring out the uniqueness. I'll try to locate and upload tonight
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rockstock
spending too much on rocks
Member since April 2019
Posts: 472
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Post by rockstock on Mar 5, 2020 18:36:46 GMT -5
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rockstock
spending too much on rocks
Member since April 2019
Posts: 472
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Post by rockstock on Mar 16, 2020 15:18:17 GMT -5
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Post by knave on Mar 16, 2020 23:22:10 GMT -5
Last two pics look like Indonesian Coral
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rockstock
spending too much on rocks
Member since April 2019
Posts: 472
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Post by rockstock on Mar 21, 2020 18:34:47 GMT -5
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