Please help me answer my questions whether such stains as on the two pictures happen to silver? Is it normal? One of the two coins is more severely stained as the other. The stains were not cleaned by soap and hot water, nor by placing them on aluminium foil in water with baking soda and salt. Back: http://members.chello.sk/ronky/a.jpg Front: http://members.chello.sk/ronky/b.jpg They are 37.05~37.1mm in diameter. They are 3mm thick (3.25mm if measuring the edge). They weight 31.27g and 31.34g. They are propelled by fairly strong neodymium magnet (but not attracted to it, and there is slight resistance). Thanks in advance for your help!
The simple answer is yes. You can also try soaking them in lemon juice for a while and gently rubbing with a cotton swab if you are worried about scratching the surface.
These are the standard bullion 1 Troy ounce "Austrian Philharmonica." I've never seen staining on these coins but I have seen similar staining on other silver coins. Bit worried about the magnet experiment as I didn't believe there should be any effect with pure silver. They are only worth their weight in silver at spot price, and nothing more, so I would polish with a jeweller's silver polishing cloth to restore their shine. I wouldn't worry about fine scratches as they are neither proof or collector coins. With similar stains on silver coins I have tried bicarb / aluminium, weak acids, pencil eraser, acetone and other solvents, boiling in soapy water and ultrasonic cleaning. Sometimes you just have to resort to silver polishing. In once instance I used a polishing tip with jeweller's rouge and a high speed Dremel power tool to completely remove the stains.
Have you tried soaking them in liquid ammonia (Homebrand Cloudy Ammonia's fine) for few hours ? Then you could try rubbing them gently with a paste made from Bicarb and white vinegar (cheap brand's ok) I find that to be very effective with stubborn stains on silver rounds and non-numismatic coins. "Bit worried about the magnet experiment as I didn't believe there should be any effect with pure silver." +1
Thanks for your responses I really appreciate them. I believe that the magnet test is okey. Not a proof that the coins are real, but at least they are not obviously fake. At least I hope I am right. The behaviour should be called "diamagnetism" http://en.wikipedia.org/wiki/Diamagnetism. Moving magnet generates electric current in coin (both gold and silver because they have lots of free electrons, therefore are good conductor) and where you have electric current you have magnetic field and therefore there is slightly repellent effect when the magnet is moved around. Check this video: http://www.youtube.com/watch?v=i4cG1SSFtXs But check for yourselves.
Even more importantly, Welcome to our Forum ! I think you are the first member from Slovakia ! Say hello to all the stackers in Bratislava !
Thanks for the warm welcome. @THUCYDIDES79 I was considering (and still a bit am) moving to Australia. Probably Sydney or Brisbane. By any chance, would you know about any job for 24yr old IT guy who's interested also in Austrian Economics?
Welcome to OZ. Id recomend Brisbane for better weather ( excl occasional floods ) Regards jobs, i cant help with that. Have a look at seek.com.au
