spiritstone
Cave Dweller 
Member since August 2014
Posts: 2,061 
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Post by spiritstone on Sept 16, 2014 23:18:34 GMT -5
Decided to cut some turtleback? agate tonight and was wondering does it display better as a flat or dome? or is there any difference. Stopped on my preform to ask for assistance in case I need to change it. As of now its a double sided flat. Thanks.   |
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Fossilman
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Member since January 2009
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Post by Fossilman on Sept 16, 2014 23:34:42 GMT -5
Nice........I think dome....
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spiritstone
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Member since August 2014
Posts: 2,061
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Post by spiritstone on Sept 17, 2014 0:34:02 GMT -5
Nice........I think dome.... I think your right. It's going to be a very low dome now. Next time I cut one I'll make it higher. |
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Post by rockjunquie on Sept 17, 2014 10:36:08 GMT -5
Higher dome will magnify the effect. Looks great, though. Nice material.
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Post by pghram on Sept 19, 2014 12:21:33 GMT -5
Nice material & cab.
Rich
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spiritstone
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Member since August 2014
Posts: 2,061
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Post by spiritstone on Sept 20, 2014 20:12:42 GMT -5
I got so caught up in the other posts I almost forgot to ask.  I had a thought and was wondering, is there any possibility that the Iris effect could become of this if cut thinner? Thanks. |
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Deleted
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Post by Deleted on Sept 21, 2014 0:47:18 GMT -5
I would cut a thin thin piece and see what happens. You will need a point source of light to see the Iris affect. The sun or a strong flash light will do it.
Jim
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spiritstone
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Member since August 2014
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Post by spiritstone on Sept 21, 2014 7:40:55 GMT -5
I would cut a thin thin piece and see what happens. You will need a point source of light to see the Iris affect. The sun or a strong flash light will do it. Jim I have a few cut off's from that cab's slab I'll give it a try on. Is there some sort of a desired thickness you could suggest for this result, or trial and error? Thanks Jim. |
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Fossilman
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Post by Fossilman on Sept 21, 2014 8:28:17 GMT -5
I have one agate that I cut,it had an Iris in it...I stuck it away,till I had time to really look at it and the rock as a whole...
Don't see them much....Mine was pretty thin too,but boy does it "POP"!.............
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Deleted
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Post by Deleted on Sept 21, 2014 11:00:33 GMT -5
As thin as you can cut it without breaking. ? 1/16. I have a bunch of tumbled Montana agate that are about 1/16 but none have the iris. Just plain oll dumb agate.
Jim
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spiritstone
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Member since August 2014
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Post by spiritstone on Sept 22, 2014 19:28:29 GMT -5
I have one agate that I cut,it had an Iris in it...I stuck it away,till I had time to really look at it and the rock as a whole... Don't see them much....Mine was pretty thin too,but boy does it "POP"!............. I'm a little confused? "You mention it had the Iris in it", I dont see that in mine. I'm unsure what i should be looking for, maybe I dont understand how this effect is caused correctly. Thanks. |
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spiritstone
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Member since August 2014
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Post by spiritstone on Sept 22, 2014 19:32:58 GMT -5
As thin as you can cut it without breaking. ? 1/16. I have a bunch of tumbled Montana agate that are about 1/16 but none have the iris. Just plain oll dumb agate. Jim A little to thin for my fingers to hold it in place on the saw. the slab was precut from the host awhile back. Going to just grind it down on the flat lap, that seems the best way for me to take it down. Chances are a dome is out of the question?or must be flat because of the thickness. |
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Roger
fully equipped rock polisher
Member since January 2013
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Post by Roger on Sept 22, 2014 20:10:26 GMT -5
I have never cabbed any of that material - but it looks like it is going to be spectacular. I can't wait to see it finished.
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Post by gingerkid on Sept 22, 2014 20:37:08 GMT -5
Hi, spiritstone! Have you taken the stone and looked at it while it's backlit by the sun to see if you can see if it has the iris effect? You may have to move it around a bit. It may be too thin to dome, but you could round off the edges. ?? Traded with @rocks2dust for a carnelian turtleback with iris-effect cab a while back. |
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spiritstone
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Member since August 2014
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Post by spiritstone on Sept 22, 2014 21:49:29 GMT -5
Hi, spiritstone! Have you taken the stone and looked at it while it's backlit by the sun to see if you can see if it has the iris effect? You may have to move it around a bit. It may be too thin to dome, but you could round off the edges. ?? Traded with @rocks2dust for a carnelian turtleback with iris-effect cab a while back. I have it down to 4.40 mm as of now with not a sign no matter what light you use. Ill keep going on the one in the pic, since its as thin as I would prefer to go on a cab of that size, and use it as my test subject. |
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Post by gingerkid on Sept 22, 2014 21:57:13 GMT -5
4.40mm is a slim and trim cab, spiritstone. Hang on tight to it while you work it and don't let it escape.  Maybe it will show the iris effect when you finish it? |
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spiritstone
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Post by spiritstone on Sept 22, 2014 22:24:26 GMT -5
Any of you have a measurement on the thickness of one that shows the effect? I would appreciate this if you did.
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Post by gingerkid on Sept 24, 2014 7:27:22 GMT -5
Any of you have a measurement on the thickness of one that shows the effect? I would appreciate this if you did. Hi there, spiritstone! Measured the carnelian and it has the same thickness as yours. If I remember correctly, I believe rocpup collects materials that shows the iris effect. He has a fantastic collection and posted pics on the forum of it (nice photography, too!). You may want to contact him. |
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spiritstone
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Member since August 2014
Posts: 2,061
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Post by spiritstone on Sept 24, 2014 8:53:27 GMT -5
Any of you have a measurement on the thickness of one that shows the effect? I would appreciate this if you did. Hi there, spiritstone! Measured the carnelian and it has the same thickness as yours. If I remember correctly, I believe rocpup collects materials that shows the iris effect. He has a fantastic collection and posted pics on the forum of it (nice photography, too!). You may want to contact him. Thanks Jan, no sense in wreaking a good cab just to find out chances are it wont work with this material. Hard to hold the stone on the lap at this thickness anyways. |
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rocpup
spending too much on rocks
Pink Limb Iris
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Post by rocpup on Sept 25, 2014 9:00:55 GMT -5
The short answer: "if the turtleback effect is thinned will it show Iris" No.
Agate is made up of very very small quartz crystals layered down layer after layer. These layers can be of different thickness and when they are just right light passing through them will diffract into a rainbow of colors. This effect can be best viewed if the slice of agate is 1/16-1/8 inch thick. The "turtleback" effect does not diffract into the rainbow because the layer of agate are of a different thickness. Again this is a short answer. Google it.
I read once that one in 20,000 agates will "Iris". I have found that in many locations where agate is found if "Iris" is found other agate from that location will have a chance of this effect but other areas does not produce this at all only turtleback.
Don
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Have a quartzy day
