Thickening Agent

Let me suggest something- bulk laxative agents with nonfermentable fiber like Citrucel. They won't ferment like the other materials often used and so won't make gas just as they don't make gas in people. This could be a little costly, but it it wouldn't take much. You might try chopped up disposable diapers as they contain a water binding polymer which I understand is fiber-like. Sawdust might be a good choic, too. I would use good white hardwood as softwoods and oak might contain resins or tannins that could atain or etch the stones. Mark H.

Ok I have to ask it. Why wouldn't you want copper in a tumbler??? What does it do?

Because it's toxic and I pour my slurry out in the backyard.

No doubt someone will chime in with their positive experience with slurry thickeners, but it seems to me it wouldn't make much difference""


The best thickener, Is Corn Starch.

Jack

Yep, it is. Reason I know this is because I keep aquarium fish Although it's not something I would put in my own tanks, copper sulfate is often used to kill fish parasites. The reason I won't use it is because of the accumulation. It gets right into everything (glass silicone and all) and you can't remove it. Nuh-uh.

Most people do not have acidic water as the water companies add phosphates et al to the water to increase buffering. Some do, though. When it doubt, test it.

My understanding is that a lot of turquoise and malachite jewelry is "backed" to keep it off the skin because of the copper content.

As for pennies -- don't put them in your mouth

Eileen

If you're licking your rocks, you're doing it wrong

I still think bulk laxatives would would well (nonfermentable. About copper- Here;s the story. Yes, it is toxic. So is iron in excess or almost any of the common metals. Cobalt compounds have been linked to heart failure when used to maintain the head on beer (incident in Canada many years ago). Chromates are known carcinogens when inhaled. Maybe not when ingested from the "health food" stores. It's all a matter of the form the copper is in and its solubility. Metallic copper is fairly insoluble, especially in alkaline, hard waterost of us have. Stomach acid can alter the composition of otherwise harmles compounds and make then into soluble, toxic compounds. So, don't eat the malachite (copper carbonate). Copper sulfate is much less inert. Trace amounts of copper are needed in our diet, excess copper deposition in tissues (as in a metabolic disorder, Wilson's disease) leads to cirrhosis and liver failure and neurotoxicity among other problems. Iron overload seen with hemachromatosis can have some of the same outcomes, plus diabetes. Children ingesting excessive iron sulfate (iron/vitamin preparations) can be seriously poisoned. Metallic copper is not particularly toxic but if you cook green beans with a little salt in a copper pan with a worn lining as I once did, your in for a nasty surprise. Major cramps, vomiting and diarrhea. I can still taste it after 25 years. Lead and mercury compounds are usually more stable and thus less bioavailable than copper. So, you get more chronic poisoning problems from slow delivery into the body than with iron or copper where the toxicity can be very acute. Copper is used as a fungicde and wood treatment in sulfate form. COpper and iron compounds can both stain in contact with the skin and that is why contact with the skin is to be avoided, not toxicity. Turquopise is a copper aluminum phosphate and not very soluble so not really that toxic in the environment. Gee I wish I had enough malachite to thicken my slurry. Of course , for the holidays you can throw in rhodochrosite scraps (manganese carbonate) and have green and red slurry to dump in your yard. How festive! Eileen has a good idea about the soapstone. It is nonacidic, nontoxic, grinds away quickly, won't sstain the rocks like malachite might, and its cheap.
Mark H.

>>My understanding is that a lot of turquoise and malachite jewelry is "backed" to keep it off the skin because of the copper content.<<

The practice of backing turquoise with metal epoxy like Devcon is to get back the weight of the stone removed cutting and polishing. It's just the way most turquoise cutters look at it. When you are buying turquoise cabs check to see how thick the backing is and think how much Devcon you are getting opposed to turquoise. Some turquoise cabs are paper thin turquoise and up tp 3/16" backing. Once the stone is set in a bezel it's impossible to see how much of it is Devcon and how much is turquoise. It's been a scam going on for decades. Myself, if I back turquoise I use a paper thin layer of JB Weld. It keeps the edges of the cab from chipping and strengthens the stone without so much weight.

Rick