NZ_Fossil_Collecta Posted February 9, 2014 Share Posted February 9, 2014 i was wondering if using a fingernail on amber is a good way to tell amber from copal, i don't want to do it wrong on one of my pieces, scratch it, and write it off as copal. i have seen it mentioned on some sites but not many, and that led me to question its viability. I'm CRAZY about amber fossils and just as CRAZY in general. Link to comment Share on other sites More sharing options...
snolly50 Posted February 9, 2014 Share Posted February 9, 2014 Fingernail? Copal is "hard" like amber; just not on a molecular level. That is, it is highly doubtful that a human could perceive the difference with a scratch. Place a small drop of acetone on a polished surface, let evaporate, touch with a tissue. Copal will be softened, sticky - amber is impervious to the acetone. That's the best method of differentiation, as copal will "pass" other tests. Human beings, who are almost unique in having the ability to learn from the experience of others, also are remarkable for their apparent disinclination to do so. - Douglas Adams, Last Chance to See Link to comment Share on other sites More sharing options...
painshill Posted February 9, 2014 Share Posted February 9, 2014 Fingernail? Copal is "hard" like amber; just not on a molecular level. That is, it is highly doubtful that a human could perceive the difference with a scratch. Place a small drop of acetone on a polished surface, let evaporate, touch with a tissue. Copal will be softened, sticky - amber is impervious to the acetone. That's the best method of differentiation, as copal will "pass" other tests. Yes. I would agree. In addition, a distinction has to be made between the tests you can employ on personal finds and simple misrepresentations about origin by a dodgy seller... versus those pieces you might have purchased where there is a suspicion of fakery. The acetone test works fine for the former but I wouldn't rely on it for copal which has been artificially autoclaved, composite glued or drilled items with faked inclusions or complete fakes made from certain plastic resins. Roger I keep six honest serving-men (they taught me all I knew);Their names are What and Why and When and How and Where and Who [Rudyard Kipling] Link to comment Share on other sites More sharing options...
NZ_Fossil_Collecta Posted February 9, 2014 Author Share Posted February 9, 2014 Thanks! Is it needed if I am just buying a common inclusion in a small piece? I'm CRAZY about amber fossils and just as CRAZY in general. Link to comment Share on other sites More sharing options...
NZ_Fossil_Collecta Posted February 9, 2014 Author Share Posted February 9, 2014 Fingernail? Copal is "hard" like amber; just not on a molecular level. That is, it is highly doubtful that a human could perceive the difference with a scratch. Place a small drop of acetone on a polished surface, let evaporate, touch with a tissue. Copal will be softened, sticky - amber is impervious to the acetone. That's the best method of differentiation, as copal will "pass" other tests. Does nail polish remover work, the active ingredient is acetone but I was wondering if other chemicals might change the reaction? I'm CRAZY about amber fossils and just as CRAZY in general. Link to comment Share on other sites More sharing options...
snolly50 Posted February 9, 2014 Share Posted February 9, 2014 I have used fingernail polish remover in the past. Of course you can't be sure what is contained in the various brands. Probably best to get a small can of acetone at the hardware store (don't breathe it and be careful storing). Yes. I would agree. In addition, a distinction has to be made between the tests you can employ on personal finds and simple misrepresentations about origin by a dodgy seller... versus those pieces you might have purchased where there is a suspicion of fakery. The acetone test works fine for the former but I wouldn't rely on it for copal which has been artificially autoclaved, composite glued or drilled items with faked inclusions or complete fakes made from certain plastic resins. painshill is of course correct. Shenanigans involving "real" but deceptively manipulated amber will not give up their lie to the acetone. A hot needle will let your nose know if it's plastic, but unfortunately there are a host of other frauds. It's a sad commentary, but it does pay to be suspicious. If you are buying, your best defense is a well respected, honest, informed dealer. Good luck. Human beings, who are almost unique in having the ability to learn from the experience of others, also are remarkable for their apparent disinclination to do so. - Douglas Adams, Last Chance to See Link to comment Share on other sites More sharing options...
painshill Posted February 9, 2014 Share Posted February 9, 2014 (edited) Acetone is most usually the active ingredient for nail-polish removers but always read the label because ethyl acetate is increasingly being used since it’s less toxic if accidentally swallowed by children (but more expensive). It’s often diluted with isopropyl alcohol for cost reasons. Also, fancy nail polish removers may have moisturising oils and perfumes as additional ingredients. Perversely, the cheaper the brand you buy, the closer it is likely to be to neat acetone. Minimising the exposure of amber to any kind of chemicals is generally a good idea. Even if the amber is old enough and hard enough (ie true amber) to resist acetone, trace amounts of other chemicals in proprietary nail polish removers may promote oxidative crazing and discolouration in the long term. Especially do not use chemicals on amber that has any visible cracks. No-one’s gonna be using sophisticated faking techniques to produce small pieces of false amber with common inclusions. Your biggest risk is from copal and (potentially younger) layered ambers - particularly those which have been autoclaved to harden them up or clarify them. A few years ago I would have been confident that autoclaved copal would fail the acetone test. I’m rather less sure today, but autoclaving also has effects on the inclusions and there are some pointers in an article I linked on another thread here: http://www.thefossilforum.com/index.php?/topic/40072-baltic-amber-autoclave-treatment/?hl=autoclave Snolly’s advice is again sound. Buy from someone with an established track record and a reputation to protect. Also – as I advised you on a previous thread a while ago – don’t buy items of this kind from someone whose principal business is amber jewellery rather than palaeontology. Edited February 9, 2014 by painshill 1 Roger I keep six honest serving-men (they taught me all I knew);Their names are What and Why and When and How and Where and Who [Rudyard Kipling] Link to comment Share on other sites More sharing options...
NZ_Fossil_Collecta Posted February 10, 2014 Author Share Posted February 10, 2014 Acetone is most usually the active ingredient for nail-polish removers but always read the label because ethyl acetate is increasingly being used since it’s less toxic if accidentally swallowed by children (but more expensive). It’s often diluted with isopropyl alcohol for cost reasons. Also, fancy nail polish removers may have moisturising oils and perfumes as additional ingredients. Perversely, the cheaper the brand you buy, the closer it is likely to be to neat acetone. Minimising the exposure of amber to any kind of chemicals is generally a good idea. Even if the amber is old enough and hard enough (ie true amber) to resist acetone, trace amounts of other chemicals in proprietary nail polish removers may promote oxidative crazing and discolouration in the long term. Especially do not use chemicals on amber that has any visible cracks. No-one’s gonna be using sophisticated faking techniques to produce small pieces of false amber with common inclusions. Your biggest risk is from copal and (potentially younger) layered ambers - particularly those which have been autoclaved to harden them up or clarify them. A few years ago I would have been confident that autoclaved copal would fail the acetone test. I’m rather less sure today, but autoclaving also has effects on the inclusions and there are some pointers in an article I linked on another thread here: http://www.thefossilforum.com/index.php?/topic/40072-baltic-amber-autoclave-treatment/?hl=autoclave Snolly’s advice is again sound. Buy from someone with an established track record and a reputation to protect. Also – as I advised you on a previous thread a while ago – don’t buy items of this kind from someone whose principal business is amber jewellery rather than palaeontology. i bought off a german dealer on eBay who specialises in both amber sculptures, and also sells quite a lot of small amber inclusions. they only have four negative ratings and all i am aware of are non-delivery based. I'm CRAZY about amber fossils and just as CRAZY in general. Link to comment Share on other sites More sharing options...
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