Enigman
starting to spend too much on rocks
Member since December 2013
Posts: 163
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Post by Enigman on Sept 16, 2017 13:41:39 GMT -5
I have completed several batches of blue apatite over the last couple of years. What is the deal with the severe quality swings on this stone? The first batches I completed did fairly well, although it doesn't get really shiny probably due to how soft it is. But lately the results are always really poor even though I use the same recipe. I recently bought some rough from a trade show that had much larger pieces than I had seen before. The rough was a beautiful medium blue. But after tumbling it became obvious that there were thin planes of really soft material that couldn't be seen in the rough state. The planes undercut deeply during tumbling and turned the stones into shapes like cauliflower, so much so that pieces crumbled off during tumbling that made the stones "do overs" that will probably end up being fountain filler.
I have also noted that there are two distinct types of blue; a dark blue-gray with rust spots that seems to be harder, and a light blue to white color that is much softer.
Can anyone tell me more about blue apatite details or some place I can specifically get good quality apatite for tumbling?
Techniques on getting consistent results with apatite?
Thanks.
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Post by gmitch067 on Sept 16, 2017 14:52:44 GMT -5
I am going to look over your shoulder Enigman at the comments to this thread.
All of my attempts to tumble both blue and green Apatite in rotary and vibe tumblers did not go well. Nothing wanted to polish. The rocks that I bought from Amazon were of poor quality. The ones I received from The Rock Shed were of better quality, but no better at polishing up... not like my first batch...
My very first try (using Amazon material) came out OK (sort-of) but were very fractured. I followed another member's advice and polished them by using cerium oxide in a DRY load with 50% stones and 50% dry oatmeal! It brought out the color nicely but the fracturing was so severe that it detracted from looks. (note: If using dry oatmeal, check the load every 6 hours to begin with. The oatmeal+cerium oxide will have been reduced to a dry powder. Keep adding more dry oatmeal until the rotary tumbler's level stabilizes)
Sooo... I am interested in what other members have to add and advise.
Thank you for posting this thread!
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georgeb138
having dreams about rocks
Member since April 2017
Posts: 68
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Post by georgeb138 on Sept 16, 2017 15:06:42 GMT -5
Here's a batch I just finished. Not super shiny but a decent luster. Skipped step one altogether. Did a few days at step 2(might go a bit longer next time) and couple days of pre-polish, and about a week(hard to tell with the damn hurricane) at polish(tin oxide). Burnished between each step for 12 hours. And used as much plastic and ceramic as I could fit in there. I'm pretty happy. I started with 3 lbs and only lost half a lb of weight in the process. Which is a huge improvement over my first batch(we don't discuss that batch). All in a Lortone QT-66.
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