Came across an old baked-bean-tin full of pre-decimal Aussie currency in a shed I was renovating. Mainly pennies and florins, some half pennies in there as well. Some of them are scratched, and all of them have some level of tarnishing, from medium to severe. Have not yet taken the time to catalogue them and check if there are valuable ones, but I was wondering if some experienced numismatists could give me some advice: *Should I attempt to clean the coins? It would undoubtedly improve their appearance, but I have heard this is discouraged since it will necessarily degrade the coin fabric *If cleaning is advised, what is the best method? *Is there a guide to rare pre-decimal Australian coins? Or is it best to just watch the markets, eg Perth Mint website? Thanks in advance!
Do not clean the coins. See above. There are a couple of books on coins values. The annual McDonalds catalogue would be your best bet for a hard copy but there are websites where you can find the mintage numbers. This one will give you ballpark values: http://www.bluesheet.com.au/Identify/
Worse case scenario is that you've just found a tin of silver. Use the calculator (http://www.silverstackers.com/calculators/index.php?page=1) to determine the silver value of those coins. Unless you stumble across something incredible, most likely it's just run of the mill circulated predecimal, but never hurts to check the dates. The bluesheet link Big A.D. gave is a useful free resource. Never clean old coins if you want to preserve any hint of collector value.
Thanks for the advice! Having had a look at a sample of a few from the top of the can, they seem to be mostly post-1945, therefore 50% silver for the Florins and Shillings. It's a real mixed bag - there are even some early decimal coins in there - here's hoping one or two of them will be a 1966 50c! I wish my predecessor hadn't chosen a tin can to keep them in - the tarnish is bad enough without rust adding to the mix!
I'm curious to learn. Now that Yeti has a pic would anyone suggest giving those a gentle cleaning now or no?
I would throw all of the post florins and shillings into cloudy ammonia for a few hours - none of them will be rare, they were mostly minted in the high or double digit millions.
Thanks for the advice. Does the ammonia bath treatment work for the coppers as well? and what are your thoughts on following up the ammonia bath with a bi-carb bath/scrub Have had a look and there's nothing special in there. Best is a parliament florin in fairly good condition, but even then probably only worth bullion.
The best ones to put in cloudy ammonia are sterling silver 925 pre 1946. Its used to break up the grime. post 1946 .50 silver still work but its destructive to the copper and your solution will turn green pretty fast with them. I like to soak 2 hours with .50 and 6 hours with sterling. Rinse well in plenty of clean water, deionized is optimum, but tap/tank water will do. With the bicarb. its an abrasive. Make sure its a nice wet paste before you start and wet the coin down or you will scratch the coin badly if applied dry. The results can be outstanding on a highly tarnished silver coin. With pennys tomato sauce works well. Vinager / coke if you want a bright coppery finish in a hurry. but the coin will eventually end up green with verdigris. Other methods are ultrasonic, electrolysis, etc ive even tried draino with a good deal of success. Aluminium and bicarb in boiling water with your silver if you just want to brighten it up and only takes a few seconds.
You have checked the dates haven't you ? If there is a valuable one in the mix, it can be sent to the US for professional cleaning and grading. So double check first otherwise go ahead and clean them up, they are beyond any general collectors quality. Edit - You have a 1927 Parliament Florin, if in general good nick that will bring you a small premium "uncleaned"
My pre-dec's have taken their ammonia bath... and laughed in its face! :lol: [imgz=http://forums.silverstackers.com/uploads/10749_image.jpg][/imgz]
