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Post by Peruano on Mar 23, 2022 17:20:18 GMT -5
Try it on a muslin wheel. It is chromoxide in a paste and hence not water soluble and works best when it heats the stone enough to melt the wax a bit and expose the oxide. It can be aggressive so use briefly on soft material and indulge a bit more on agate. If you have pits the green wax will embed and stay conspicuous until scrubbed judiciously.
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Post by Peruano on Mar 22, 2022 15:08:55 GMT -5
I have some Kimberlite diamond matrix which I scooped up out of the free pile at the Kimberly Mine in South Africa. Oh, and I should add that it has not diamond material in it, because the mine xrays all ore to spot diamond before the kimberlite is discarded in the tailing pile. I guess I'll just call it Kimberlite. I bought a couple of cool tumbled rocks in the rock shop at the mine as well. They are pretty jaspers and small piece of blue hawkseye (they don't have diamonds either), darn.
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Post by Peruano on Mar 17, 2022 16:05:09 GMT -5
One sentence for three photographs is what I call focused writing or brevity.
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Post by Peruano on Mar 17, 2022 9:14:51 GMT -5
I've had this specimen for a quite awhile, but never associated it with turtleback agate, but from the discussion here it seems to be a likely candidate. The facets are in the thin carmel layer and the alternating banded layer immediately beneath. The thickest carmel layer has the rough texture of so many volcanic and agate formations. Its from southern New Mexico in the Apache Creek area. Ideas?
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Post by Peruano on Mar 17, 2022 6:09:43 GMT -5
waterboysh you may have missed the point in my hurried scribblings. See the quartzpage.de Google is your friend (sometimes) I don't carry the exact url for the quartzpage but google will lead you there. If you explore the page it will give insights, technical info, and photos of just about every variety of rock made of rock/gem in the quartz/chalcedony umbrella including tiger eye, hawkseye, and yes cat eye. Its a powerful resource and focused exactly on many of the stones we work with, admire, and try to understand. I hope you did not interpret my guidance as smug. That was not my intent.
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Post by Peruano on Mar 16, 2022 14:10:04 GMT -5
The real advantage of the Raytech over just about all the rest is having the saw table lift up easily with a plastic bowl underneath that is easy to dump, clean, and dry. So much easier at the end of the day.
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Post by Peruano on Mar 16, 2022 14:05:25 GMT -5
Yes, it will show up as a message, maybe even to your e-mail account if you have selected that option. Welcome
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Post by Peruano on Mar 16, 2022 6:30:21 GMT -5
Read about them, but briefly the blue is Hawkeye and the asbestos fibers exposed is less silicated than the golden tiger eye where it has been replaced by silica. Reddish material can occur without any heat treatment and in the same slab as the more golden variety. Its wonderful stuff even tho quite common in the trade. See the quartzpage.de Google is your friend (sometimes)
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Post by Peruano on Mar 15, 2022 19:01:40 GMT -5
A personal experience. I traveled to Peru (south of Lima) in the early 1980's to salvage leatherback turtle carcasses that had been butchered, discarded, and mummified on an area behind a fishing port. I was interested in skeletal material but was able to superficially examine gut contents in the shells that had dried on the beach. Fully 13% of the individuals examined had plastic bags and other plastics in their guts (and we probably undersampled due to the dubious manner in which the turtles had been discarded). Remember these were the ones that were harvested alive by the fishermen (the ones that died from gut impactions must have been on the bottom of the ocean. In many cases the plastics were twisted into knots that would have soon occluded the gut and interfered with digestion. Note that leatherbacks eat jellyfish and plastic gabage bags are similar to floating jellyfish. Also important is that this was along a very sparsely populated coast of South America. What must it be like off Mexico, New York, or Europe?
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Post by Peruano on Mar 15, 2022 17:14:40 GMT -5
Many Brazilian agates have a dark rind of variable thickness and further in have a boring grey matrix. If you cut tangentially instead of just across the rind you can increase the amount of dark matrix relative to the interior grey and with imagination can produce scenes. Here are three examples. What looks like yellow scratches are color variations in the dark matrix. What is required is that you remove proportionally more of the interior grey thus accentuating the angle of exposure of the brown rind. Am I trying to hard?
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Post by Peruano on Mar 15, 2022 16:54:55 GMT -5
Need I say it works.
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Post by Peruano on Mar 15, 2022 16:54:21 GMT -5
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Post by Peruano on Mar 15, 2022 16:50:31 GMT -5
jamesp I'm very confident that the stingray coral is different from Petosky stones. Here is a link to numerous Petosky photos (jugglerguy's avatar is superb. The Petoskys have a distinct border between polyps where that border is lacking in Stingray. As to degree of silica content the stingray grinds fast but takes a good polish. I'd say the rays are silica and perhaps some of the matrix remains as calcium based minerals.
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Post by Peruano on Mar 15, 2022 10:54:17 GMT -5
Scrounged up the slabs of stingray coral from Indonesia. Don't judge a book by its cover. It surprised me the detail that was preserved. The orange spots seem to be randomly present.
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Post by Peruano on Mar 14, 2022 5:43:12 GMT -5
This is a sponge coral given to me by a friend who if I recall said it came from Morrocco. Soft coral but pretty. Here are two views of a horn coral collected on a bluff above the Rio Grande south of Belen, NM. Like the Utah material but not as red and not as well preserved - but to my knowledge exceptionally rare in NM> I have some material from Indonesia commonly called stingray coral which I will dig out and include when I have a chance. I have cut a piece of the reddish material that Bev (Beth!) showed here. The piece I slab (and will send back to her) had big holes like they may have been bored, but there was no obvious detail to suggest that the material was coraline.
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Post by Peruano on Mar 13, 2022 12:37:42 GMT -5
Its a worldwide problem and long since out of hand.
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Post by Peruano on Mar 13, 2022 12:32:02 GMT -5
I also meant to add that you should monitor your material frequently when you first start out. If it is soft, the slurry will thicken quickly and the action will lock up requiring you to add more water to loosen the action somewhat. Almost all vibes can be run without the top in place allowing better observation of the action; however they tend to dry out a bit more sans top (at least in the arid SW USA they do). Again good luck.
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Post by Peruano on Mar 13, 2022 12:26:00 GMT -5
Being originally from the Midwest, and having lived most of my life in the SW, I had to google quahog clams just to see what the shell was like. Tommy is likely correct that they will be softer than most rocks we like to use for lapidary, however that is not a guaranteed result. I have worked alot with shell/mollusc products collected on Mexican beaches and some of them are quite hard. Your clam shells have lots of growth rings/grooves and the ridges will probably polish faster than the valleys. However its a wide open field and you probably have lots of shells with which to experiment. The vibratory tumbler you would use would be partially determined by how big the shells are. Some vibes have a center post in the middle of the bowl like an angel food cake pan. Thus a bowl 6" in diameter only has a space of around 2.5" all around that post, the result being that things bigger than 2.5" might lodge, fail to move adequately, and even wear a hole in the bowl due to constant contact with one particular spot. So consider size limitations when you select. I get some pretty big stones or shells in my Raytech Vibe 5, but the bigger model might be needed for your use. I like the Vibe 5 because its about the cheapest of the real vibes (cerca $100). The minisonics might do -- they don't have a central post and large material oscillates pretty well in them. In terms of technique, I'd not use anything coarser than 100 grit, use something to cushion the action enough (ceramics, or even pistachio shells). I normally don't recommend plastic tile spacers but they might be perfect for you if your shells are soft. I find my mollusc material takes a great shine after only a couple of stages in the vibe (say 600 grit) and then being hit with a zam (chromium oxide) muslin buffer wheel. The zam is the chrome oxide in a wax base and can be aggressive so pay attention to heating up on the wheel (I touch the shell to my cheek for temp check). These are the stones as they come out of the vibe and after a zam polish. The ones below may not have seen the zam treatment yet. You can probably see where ridges have been worn away on my material (by the ocean's action - not by my vibe), but the polishing does highlight the shells detail and microcrystaline structure. Your results may vary. I can say mine to from batch to batch and shell to shell. I will say that many folks caution against breathing the dust from shells so dispose of your vibratory water and rinses to avoid ingesting them by breathing or ingesting. I'm not sure its harmful but urban legends have legs even when not based on facts. Please keep us informed of your results. Curious minds want to know.
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Post by Peruano on Mar 12, 2022 9:51:10 GMT -5
I borrowed a vintage one from a friend. After investing a few $$ worth of batteries and fiddling with a bunch of material that I was pretty sure should have some reactivity, I convinced myself it was a process that was not worth it for what it was telling me. I have my mother's orange fiesta ware on the shelf so I'm not going to worry about rocks in the shop.
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Post by Peruano on Mar 11, 2022 16:46:48 GMT -5
If a blade is being deflected, it is possibly vice alignment relative to the saw blade Pushing too fast relative to the cut rate could cause a slight shift in the rock but this would not be a constant or subtle effect, but would cause the saw to slow, bind, or shriek. Is your blade securely bushed on the arbor and does it have the proper sized flange bushings on each side?
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