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Post by rockyraccoon on Feb 8, 2004 22:04:44 GMT -5
this mix of rocks is giving me the devil! i'd say 1/4 of the load is ready for polish; 1/4 looks worse than when it started - holes, fractures, cracks; and 1/2 has some little flaw like a tiny rough spot or what looks like someone stuck a fingernail into it (i'm assuming that means other rocks scratched them). so are the ones ready for polish the harder stones and the ones that fared the worse the softest stones in the load? to get the small flaws out of the majority of the rocks would you go back to step one for just a few days. they are perfect on 3 sides with a tiny flaw on the other side. i don't want to lose any size but don't think step 2 will get these knicks out. should i start a whole new mix load and throw these in just as they are almost through with step 1?
kim
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donwrob
has rocks in the head
Member since June 2003
Posts: 509
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Post by donwrob on Feb 8, 2004 23:02:39 GMT -5
That is a good question, and a matter of personal preference. I finish a lot of rocks that have imperfections in them. For me, there is only a small percentage of rocks that finish as nice as I'd like in any given batch. A good many of them are good on 3 sides or have small fractures. Sometimes this adds character, sometimes it just makes them ugly. And, my guess would be that the best looking ones are the softest, and the harder ones are the others. Also, rocks that fracture (get the thumbnails) aren't always per say softer, but may be high in silica and have concoidal fracturing properties. The fracture you see most likely is part of a hertzian cone that didn't have enough energy to finish when it formed. I suppose if you want to get the most perfect rocks from a load, you need to set aside the ones ready to move on, and re-run the others with new ones added in until you have enough that are ready for the next stage. I usually just run a batch through start to finish, only removing the ones I feel there is no hope at all for. After they are finished all 4 stages, I throw any that are just plain ugly back in the beginners pile. I hope this helps some, good luck, Don
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WarrenA
fully equipped rock polisher
Member since November 2003
Posts: 1,530
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Post by WarrenA on Feb 9, 2004 0:03:57 GMT -5
I will agree with don and say run them through and sort off what you don't like no need to hold back a batch for just a few duds
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Post by puppie96 on Feb 9, 2004 1:29:28 GMT -5
I've been forwards and backwards so many times with my saphs and rubies that I'm lost. I've done the same thing with my emeralds, but in that case I was trying to make an already good result better. Not the case with the stubborn saphs!
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MichiganRocks
starting to spend too much on rocks
"I wasn't born to follow."
Member since April 2007
Posts: 154
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Post by MichiganRocks on Feb 9, 2004 10:12:21 GMT -5
Hey Kim, I understand your frustration! Been there, done that. It took me a while to get the hang of spotting problems before they ruined a whole load. As a rule, I only go to polish with rocks that at least appear to have no holes or sharp edges. They also must "feel slippery" to me. A hard stone that is rough, will just make other stones rougher. It's kind of amazing how many flaws still appear. I agree with Don, only a small portion really measure up to my standard and become available for jewelry and similar uses. The rest go to display dishes and containers in the house or are given away. Your Dalmation pictures look good! Ron
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Post by rockyraccoon on Feb 9, 2004 11:42:38 GMT -5
i sorted and felt and sorted and felt last night. i think i'm going to run them all in polish but i still have them separated since in the midst of all this frustration i filled another barrel with fresh mix and started them up in the spot these were tumbling. i think i'm being to hard on them. the rejects are not shown as i'm postive they won't go to polish. some of them had holes that the pellets were stuck in. where pellets can get grit can surely get. 1 lb of these came with the toy and the rest we picked out of the driveway gravel to start the 6# tumbler. these are the ones that i know are ready for polish: these are the ones that i wasn't sure about: can you put them in the rockbed polished or do you need to put the unpolished rejects in there? kim
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MichiganRocks
starting to spend too much on rocks
"I wasn't born to follow."
Member since April 2007
Posts: 154
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Post by MichiganRocks on Feb 9, 2004 18:25:17 GMT -5
Some rocks that you collect from the ground have inclusions that are much softer than the host mineral. They look interesting, but no matter how long you tumble, they will still have holes. They will for sure carry grit to your polish and I always throw them out. Hard to tell from a picture, but I agree that maybe you're being a little hard on them. As long as anything that could carry grit is weeded out, the rest could just go to polish. Then separate out the ones that don't polish to run together later. Rocks with sharp edges (can happen during polish also if a fracture line breaks) are mainly a problem with nicks rather than general polishing quality. If a fracture looks like it might separate, it's usually a good idea to cull it for hand grinding or splitting at the fault into two rocks. Make sure that you have enough pellets to protect from impact damage from the larger rocks which will increase the fault opening problem and can cause the "fingernail cuts" that you described.
Ron
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