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Post by vegasjames on Feb 10, 2019 20:59:55 GMT -5
I think this is a granite I found the material in Southern California.  DSC_0737 by James Sloane, on Flickr |
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gatorflash1
spending too much on rocks
Active in Delaware Mineralogical Society, Cabchon Grinding and Polishing, 2 Thumlers B's and a UV-18
Member since October 2018
Posts: 375
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Post by gatorflash1 on Feb 13, 2019 16:10:27 GMT -5
That's dramatic!
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Fossilman
Cave Dweller 
Member since January 2009
Posts: 20,723 
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Post by Fossilman on Feb 17, 2019 10:28:11 GMT -5
Every trip I make to Montana, I always bring home some of this material... It does a great job in the tumblers...
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on Feb 17, 2019 11:13:14 GMT -5
Having grown up in California, and seen so much Granite in places like Yosemite and everywhere else, it does not really occur to me to pick it up.
Recently though I have found some really pretty pink, black and white granite in the field, and brought most of it home for the back yard as decoration. But I decided to tumble some of it a few weeks ago. While it is all still in Stage 1 for a bit longer, I am excited to see how it polishes!
Also thanks to those above, who just educated me on a new term "undercutting", and why Granite is so predisposed to doing it!
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Post by Jugglerguy on Feb 17, 2019 12:16:41 GMT -5
Here’s a picture of my very first finished batch.  |
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gatorflash1
spending too much on rocks
Active in Delaware Mineralogical Society, Cabchon Grinding and Polishing, 2 Thumlers B's and a UV-18
Member since October 2018
Posts: 375
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Post by gatorflash1 on Feb 18, 2019 8:27:45 GMT -5
That's a great looking batch with lots of color, especially orange. What was your recipe?
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Post by Jugglerguy on Feb 18, 2019 16:28:35 GMT -5
That's a great looking batch with lots of color, especially orange. What was your recipe? It’s been forever since I did those, but the recipe was basically what I do now. I roughed them in a rotary, then moved to the Lot-O. Lot-O steps: 2 days with 2 TABLEspoons 220 silicon carbide 2 days with 1 TABLEspoon borax and 1/2 TEAspoon of 500 aluminum oxide 2 days with 1 TABLEspoon borax and 1/2 TEAspoon of 1000 aluminum oxide 2 days with 1 TABLEspoon borax and 1/2 TEAspoon of aluminum oxide polish You can eliminate the 1000 step and just do three days in 500 instead. I rinse with about a quarter cup of water and a tablespoon of borax between each stage and use a separate bowl for polish. |
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on Feb 19, 2019 18:57:20 GMT -5
Now I think I'm going have to start collecting and putting aside granite for a future batch. All of these pictures are really interesting and have a lot of character. Thanks for posting the pictures.
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gatorflash1
spending too much on rocks
Active in Delaware Mineralogical Society, Cabchon Grinding and Polishing, 2 Thumlers B's and a UV-18
Member since October 2018
Posts: 375
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Post by gatorflash1 on Feb 24, 2019 8:52:53 GMT -5
Rob thanks for the recipe for the granite. Did you use anything special in the polishing stage other than borax? I read that using Chromium Oxide for the final polish doesn't cause undercutting on granite. Has anyone ever tried this? I'm going to give it a shot as I have many pounds of beautiful granite scraps that I obtained for free from several local granite counter top businesses. They are just too colorful and with excellent patterns and grain to ignore!
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Post by Jugglerguy on Feb 24, 2019 12:16:33 GMT -5
Rob thanks for the recipe for the granite. Did you use anything special in the polishing stage other than borax? I read that using Chromium Oxide for the final polish doesn't cause undercutting on granite. Has anyone ever tried this? I'm going to give it a shot as I have many pounds of beautiful granite scraps that I obtained for free from several local granite counter top businesses. They are just too colorful and with excellent patterns and grain to ignore! I've never heard that, and I've never used chromium oxide. I'd love to hear how it turns out. |
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