I've tried to study this a bit, including polishing some shells myself to see how they react in attempts to better detect tampering in shells I buy. I suspect the best way to easily discover enhanced shells is with a stereoscopic microscope. However not everyone is willing to go that far. An easy way to detect enhancing is to turn the lights out at night and shine a flashlight on the suspected shell sitting next to a known all natural shell for comparison. This highlights imperfections not normally noticed during the day. You can see micro scratches from polishing, brush strokes from painting, and a lot more natural flaws as well. Detecting painted shell get's tougher the better quality the paint job. I look at as many specimens as I can to build up a repertoire of what possible variations the pattern could be. After you have a good repertoire, you can spot poor fake patterns easier. Take a look at this shell from the top fake shell distributors on ebay. http://cgi.msn.ebay.com/ws/eBayISAPI.dll? ViewItem&category=4838&item=6502355306&rd=1 When spoting painted shells especially notice if the species has a pattern that is both on the margin and the dorsum. If not, watch for over- painting onto the margins. Also watch for three dimensional spotting. Spots can be painted on different layers of clear coat, giving them a three dimensional look that the natural pattern doesn't have. Poorly painted shells have detectable problems. The longer the shell has been dead, the harder it is to make it look live collected. In many cypraea species the margins have been built up by the animal more than the dorsum. After death, the margins begin to separate from the dorsum. The area where the dorsum and the margins meet seem to be near impossible to "polish together" once separation begins. Look carefully at this crucial area where the margins and dorsum meet for unnatural lines. Higher quality fakes overcome this "nacre separation" problem by building up margins out of synthetic material. I guess the stuff is some type of polymer. A master's work is extremely tough to detect by the naked eye, but it will feel different in the hand than a natural shell. It will most likely will weigh less than it should because the polymers are lighter than calcium carbonate. Some of these polymers will generate static electricity and pick up particles if rubbed like the old comb trick. ---------------------------------------------------------------------- [log in to unmask] - a forum for informal discussions on molluscs To leave this list, click on the following web link: http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1 Type your email address and name in the appropriate box and click leave the list. ----------------------------------------------------------------------