rockinmom
spending too much on rocks
Member since January 2007
Posts: 481
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Post by rockinmom on Jan 15, 2007 21:06:07 GMT -5
Hello there. I'm wondering if someone could help me? I have some rough Moonstone that I would like to tumble. It ranges in size from 1.5cm to 6cm. Does anyone have any suggestions on how to tumble this. We have a 3lb lortone tumbler. Also, I have some rough kyanite .5cm to the largest piece is 3cm. Any thoughts on this? Thank you! Tammy tumbler for only 1.5 months.  |
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turnedstone
freely admits to licking rocks
Member since January 2006
Posts: 766
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Post by turnedstone on Jan 16, 2007 18:29:33 GMT -5
Hi Tammy well never tumbled Moonstone or kyanite. Moonstone is about 6.5 on the mohs so it should tumble all right. Kyanite could be a bit of a challenge it has 2 different hardnesses it runs 4.5 along the crystal axis while across the axis it can run 6 to 7. I have polished it on my pixie so it will take a polish just do not know if you can tumble it. Hope this helps.
George
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donsimpson
starting to spend too much on rocks
Duncan and Mari's Dad
Member since September 2006
Posts: 176
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Post by donsimpson on Jan 16, 2007 18:34:24 GMT -5
I'm by no means an expert, but I can share my experience with tumbling moonstone. The first time I went to a local rock shop, I was smitten by the moonstone, and, although it was $1 / oz and the owner warned me it was difficult to tumble, I bought two lbs. Following a standard five stage process (60/90, 120/220, 400, pre-polish, polish), the rocks came out beautifully polished. I mean really stunning. However, EVERY SINGLE piece was cracked and/or chipped (the pictures don't quite convey how bad it is up close).  Bigger picture here: www.alliancebusiness.com/graphics/moonstone.jpgThat was before I discovered this website: users.frii.com/ajs/RockTumbling.htm and this message board. I didn't know about using buffering agents like plastic pellets, and I didn't understand the issues with tumbling "softer" rocks like feldspars (MOH 6). So my plan now is to practice with less expensive and easier to tumble material in the quartz family (MOH 6.5 - 7) before I get some more and try again. D |
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rallyrocks
fully equipped rock polisher
Member since November 2005
Posts: 1,507
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Post by rallyrocks on Jan 16, 2007 18:39:00 GMT -5
I'd beware of stuff like Kyanite with different hardness based on orientation, tumbling is really random abuse and tends to destroy materials that want to break up along cleavage planes.
I have seen one or two cabs cut from Kyanite crystals, but never seen any that made it through tumbling
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rockinmom
spending too much on rocks
Member since January 2007
Posts: 481
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Post by rockinmom on Jan 16, 2007 18:48:49 GMT -5
Thanks all for the advice. I may hold out on the moonstone for a little while until I have a little more experience. Not like it's going to go anywhere! But, am I really patient enough!? lol The kyanite is so small.. I don't think tumbling it would do any good. It's pretty dirty tho.. I will post a separate entry on how to clean it maybe. Thank you all again. Tammy |
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rockinmom
spending too much on rocks
Member since January 2007
Posts: 481
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Post by rockinmom on Feb 4, 2007 13:57:16 GMT -5
I have recently discovered this is blue flash moonstone. Is the hardness of it different then say and tan moonstone or is it all the same? Just looks like it would chip away so easy. But, I suppose I could just do a rough tumble for a couple of days right?
Thanks. Tammy
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donsimpson
starting to spend too much on rocks
Duncan and Mari's Dad
Member since September 2006
Posts: 176
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Post by donsimpson on Feb 6, 2007 13:07:31 GMT -5
My understanding is that blue flash is a feature of a given piece of moonstone (I've also seen cat's eye), and that it is the same material.
Be sure to use lots of plastic pellets (or similar) buffer to reduce chipping.
D
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