transcendental
spending too much on rocks
Member since June 2014
Posts: 459
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Post by transcendental on Aug 18, 2014 10:19:38 GMT -5
So far my luck with getting a good finish on quartz is subpar to put it nicely. I had some bloodstone, agate, carnelian and amazonite in the mix which came out beautiful. Even the amethyst I had in there isn't great, actually did a better finish by hand with sandpaper.
I'm know the quality of what you put in will ultimately dictate the quality that comes out, and I knew alot was going to be more like filler rock than usable polished stones by the end of the run. Got a better finish this run than my last but not by much. Problem isn't so much the finish on the stones but internal fractures which I had hoped spending longer in course and medium grit would help to smooth out where they reach the surface of the stones. Anyways, not a total loss. All the moonstone I had in there which was the main stones i wanted polished came out great. Just had higher hopes for the quartz and even that I got a few nice pieces out if the batch. It's a learning experience
So my question is, what's the most challenging stones you all have tumbled? (Aside from obsidian... I've read in other posts it's hard to get that glass like finish)
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tkvancil
fully equipped rock polisher
Member since September 2011
Posts: 1,546
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Post by tkvancil on Aug 18, 2014 10:44:39 GMT -5
Labradorite ..... 5 pounds turned I into about 2 pounds during the "coarse" grind. Coarse in quotes because I started with 220 in the rotary. They shaped nicely but were full of fractures. Not from the tumbling, but nature of this particular feldspar I think. There were also lots of tiny pits or spawls on the surface of many of the rocks which never seemed to want to tumble out. I finally said enough is enough and took them through to polish with lots of cleaning between stages. Out of 90 or 100 pieces I got out about 10 that I liked. Having said all that I will roll another batch someday. It's a beautiful stone and I think I have learned some things since my first attempt. A pic of one of my "keepers" flaws and all ....
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transcendental
spending too much on rocks
Member since June 2014
Posts: 459
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Post by transcendental on Aug 18, 2014 10:53:02 GMT -5
I don't feel so bad about my batch after you say you kept 10 out of 100... sounds like the batch I just ran. Man that's a beautiful stone, even with the flaws
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Post by Jugglerguy on Aug 18, 2014 15:35:41 GMT -5
Obsidian isn't hard to tumble, at least in a vibe with Krystee's (TNTmom) instructions.
I have a bunch of Kona dolomite which I have never successfully tumbled. I've tried three or four times with Connrock's advice along the way and I never did get it to come out nice. I'm not sure that it's even possible to tumble it. If anyone knows how, I'm all ears.
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transcendental
spending too much on rocks
Member since June 2014
Posts: 459
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Post by transcendental on Aug 18, 2014 20:58:09 GMT -5
Hmmm... maybe what I read was about tumbling obsidian in a rotary. Think kona is too soft for tumbling? Isn't it like a mohs 4? Can you link to connrocks post plz, you've pealed my curiosity
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Post by Jugglerguy on Aug 18, 2014 22:54:41 GMT -5
Connrock tutored me through a series of emails, so there is no link. I do think Kona is too soft. It is about MOHs 4. It always looks good until 500 grit, then it goes down hill.
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transcendental
spending too much on rocks
Member since June 2014
Posts: 459
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Post by transcendental on Aug 19, 2014 12:59:12 GMT -5
Have you tried hand polishing after 500? Either literally elbow grease and sandpaper or with a motorized polishing wheel?
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Post by Jugglerguy on Aug 19, 2014 16:03:33 GMT -5
Yes, they polish nicely on my flat lap.
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transcendental
spending too much on rocks
Member since June 2014
Posts: 459
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Post by transcendental on Aug 19, 2014 16:58:14 GMT -5
Glad to hear it
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