hh5
starting to spend too much on rocks
Member since January 2012
Posts: 136
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Post by hh5 on Aug 25, 2019 20:14:23 GMT -5
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Deleted
Deleted Member
Member since January 1970
Posts: 0
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Post by Deleted on Aug 25, 2019 21:54:06 GMT -5
Looks like the same mix of colors in both the matrix and beryl/emerald as in some of the Brazilian emerald specimen pieces I've had.
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Post by rmf on Aug 26, 2019 2:50:00 GMT -5
hh5 The first thing I would do is take a quartz crystal (known hardness of 7) and see if I can scratch the greenish area. Emerald should be hardness of 7.5-8. If you have a piece of topaz (known hardness of 8) I would try the same thing. Noting the differences. The color is within the range of emerald. The slabs are actually harder to tell the true color due to the finish. The black does not look as black as I would expect but given the sawed surface I think that texture may be the issue. You should get a nice mirror polish on it at 8000 diamond. The color could also be jade and some of the edges look like that to me. the real proof will be the hardness test, then how it finishes. Does it finish out like jade or emerald. you will probably notice a big difference in how the shine appears moving from 1200 grit to 3000 grit to 8000 grit. If you have already cut a number of jade cabs and previous emerald then you will see the difference there. To me emerald cuts very easily and the polish just pops out with little effort once you hit 8000. Jade tends to orange peel a bit and takes more work.
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Post by greig on Aug 26, 2019 6:54:46 GMT -5
I bet this slice would look nice with a strong light (eg flashlight) behind it. My first thought was Nephrite Jade, so it might includes Actinolite. As such, don't breathe the dust when working on it, as it might contain asbestos-like fibers.
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hh5
starting to spend too much on rocks
Member since January 2012
Posts: 136
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Post by hh5 on Aug 27, 2019 10:30:03 GMT -5
Got a set of Mineral Labs hardness points so I tested this material on the green area. Would not scratch at 7 did scratch at 8.
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hh5
starting to spend too much on rocks
Member since January 2012
Posts: 136
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Post by hh5 on Aug 27, 2019 11:47:27 GMT -5
@ Greig, Strong light behind it does not show through, at this thickness .43" The material is opaque.
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