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pennyante
New Member
10 Posts |
 Posted - 08/01/2010 : 12:02:47
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I ran out of space in the subject line! Are there any household chemicals that can be used to tell if something is definitely silver? Do I have to buy a test kit? This will undoubtedly sound REALLY odd but I got a partial denture in a junk box at an auction. Instead of the pink plastic stuff it is made of a silver-colored metal. I checked on the web and found one dentist's site that said hammered silver was used originally for that purpose but that today they typically use a chrome cobalt alloy. Both chrome and cobalt are attracted to a magnet...right? This isn't and it does look pretty old (the teeth are even worn down)! Could it be???
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messymessy
Penny Sorter Member
88 Posts |
Posted - 08/03/2010 : 20:53:53
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This is going to sound strange, but I used to be able to distinguish between silver and other metals based on pitch. Silver has a higher pitch when dropped than other metals. I suppose this would only help if you had something of similar size and shape to compare it to.
Buy a silver test kit on Ebay. I think I paid $6 for mine (including shipping). |
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bigfuzzybelly
New Member
USA
5 Posts |
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Beau
Penny Pincher Member
216 Posts |
Posted - 08/04/2010 : 15:28:36
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| it is probably titanium, I had a set made that did not fit and they are titanium. |
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bruce hylton
Penny Pincher Member
USA
102 Posts |
Posted - 08/04/2010 : 18:15:51
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| Could also be platinum. |
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Dr. Cadmium
Penny Sorter Member
USA
26 Posts |
Posted - 08/04/2010 : 21:35:58
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Note that some older dentures are made of palladium, which would be a nice find.
1) Test with a magnet.
If magnetic, you have some kind of steel alloy.
If non-magnetic, proceed to next step.
2) Spark test. (If you suspect precious metals, chemicals are a less destructive option)
Titanium is the easiest to recognize here. It produces distinct white sparks. It's also a very light metal like aluminum.
Orange or red sparks indicate various stainless and nickel/cobalt alloys.
If it does not spark, you probably have silver or palladium, but there are other tests that need to be done.
Chrome is almost always used as a coating or mixed with other metals to form an alloy, so usually the base metal involved will have a larger effect on magnetism. Pure cobalt is magnetic, but it's also usually alloyed with other metals, sometimes producing nonmagnetic alloys. |
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wolvesdad
1000+ Penny Miser Member
USA
2164 Posts |
Posted - 08/04/2010 : 22:40:58
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| good info Dr. Cadmium |
"May your percentages ever increase!" |
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pennyante
New Member
10 Posts |
Posted - 08/04/2010 : 22:53:19
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| Thanks! I didn't know anything about a spark test. I googled it though. Very handy info! |
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thogey
1000+ Penny Miser Member
USA
1617 Posts |
Posted - 08/04/2010 : 23:05:44
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How do you make the sparks?
Dremmel? |
Come to the new and improved realcent: http://realcent.org
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pennyante
New Member
10 Posts |
Posted - 08/04/2010 : 23:19:01
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| From what I read on google they use a grind wheel. I don't know if a dremmel would be fast enough...it specified a minimum speed. I'm wondering if one of the Cash for Gold places would have the chemicals to test it. It would be kinda embarrasing to carry in false teeth but ... |
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simplicitycounts
Penny Hoarding Member
USA
535 Posts |
Posted - 08/05/2010 : 09:51:20
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| Ask somebody with an XRF gun what they would charge you to test it. Market Harmony tested a chain for me and gave me the breakdown for it for $5 shipped back to me. Then you're just out that and the postage to ship it there. Then you know for sure, no messing around. |
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pennyante
New Member
10 Posts |
Posted - 08/05/2010 : 11:25:52
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| Boy I'm having to google a lot in this thread! The XRF would be a great option but I don't want to mail these things anywhere lol. Guess I will have to break down and buy a chemical test kit. With the idea being that I would likely sell these .... I don't think many people would want to trade for a hard to id metal in a TEOTWAWKI it situation esp in the form of dentures!...who would buy such a thing? |
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Dr. Cadmium
Penny Sorter Member
USA
26 Posts |
Posted - 08/05/2010 : 21:01:25
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A dremel or similar rotary tool definitely spins fast enough, and it's less destructive than putting something like this to a much larger grinding wheel. The sparks won't be as big as with a wheel but it still works fine for a spark test.
An X-ray gun is the most definitive method for any material. Not exactly household equipment though.
Assuming this is a not a very light metal (aluminum or magnesium), which usually are not used in an item like this anyway, the next test after a negative spark test is a chemical test.
One common chemical test: Add a drop of nitric acid, then follow up with a drop of hydrochloric acid. Silver and silver-plated items will produce a white flash or precipitate in the solution. These chemicals are available in hobby stores and jewelry test kits (as suggested above). If the nitric acid produces a strong reaction by itself you have a different metal.
Acids can be dangerous, especially in high concentrations. A simple jewelry test kit is your best bet if your chemical knowledge is limited. It's still a good idea to do a spark test first in case it's stainless. |
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Dr. Cadmium
Penny Sorter Member
USA
26 Posts |
Posted - 08/05/2010 : 21:03:24
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| Suggestion when doing a spark test: practice on a few items you know the composition of first. Try something magnetic like steel, and then something you know is aluminum like a lawn chair or aluminum can. |
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hobo finds
Penny Hoarding Member
838 Posts |
Posted - 08/05/2010 : 21:15:39
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| Kurr posted something on spark testing. I just can not find it!!!! |
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hobo finds
Penny Hoarding Member
838 Posts |
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any definitive homemade way to tell silver?
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