Easy Way For An Amateur To Determine Metal Composition?

[lxskllr]

I found a metal thing in some rubble today. I'm kind of curious what it is, and what it's made from. Probably aluminum, but are there any household chemicals that can be used to test the metal? I 'll have to clean it up later and see if there's any interesting markings. It has a styllized 36 on it.



:shrugs:

 

[deadlyapp]

I'd check first to see if magnetic. If it's a stainless steel or steel, there are liquid drops that can be used to check composition. Outside of that without a PMI gun or taking to a testing lab, not much you can do.

 

[highland145]

Size?

 

[lxskllr]

3" dia, and ~¾" deep. Kinda looks like a lid to a snuff can.

 

[gorobei]

you could try burning them and looking for color spectra from a slit/diffraction grating. but you would need a controlled temp flame to be consistent. tin, zinc, aluminum, steel dont have wildly different colors sadly. you can also try with a grinding wheel on the metal.

acid test will id zinc or magnesium. the bigger issue will be if it has a chrome plating as that usually gets a copper/nickel plate first to give it something to grab onto..

 

[sdifox]

It's Krypton.

Krypton | Kr (Element) - PubChem

Chemical element, Krypton, information from authoritative sources. Look up properties, history, uses, and more.

pubchem.ncbi.nlm.nih.gov

 

[biostud]

U-235

 

[biostud]

It is not iron, copper, gold or quicksilver.

 

[Charmonium]

U-235

I think that was submarine Hitler took to Argentina [whistles by]

 

[[DHT]Osiris]

You can also grind it, or if you're really insistent you can heat it with a controllable temperature until it melts or you die from whatever it off gasses.


There are many such spark charts available online for various metals, this was the most comprehensive one I found in less than a minute.

 

[[DHT]Osiris]

So, I feel like I'm going crazy, I think I know that emblem but I can't place it. The top of the '3' is drawn the way Chevy does their Z for their vehicles which would make me think that was a stylized Z06 emblem but I can't find any trace of it on the internet.

 

[lxskllr]

The metal's very soft and malleable. It's pretty light, but it's also pretty thin. My first thought was silver. It also seems like it could be a decorative cover on something, but I don't know what. I mentioned a snuff lid, but it's so soft, I'd think it would get beatup in daily use. I left it out in the truck, and I don't know if I feel like getting it this evening to start getting it cleaned up. Maybe I will.

 

[[DHT]Osiris]

The metal's very soft and malleable. It's pretty light, but it's also pretty thin. My first thought was silver. It also seems like it could be a decorative cover on something, but I don't know what. I mentioned a snuff lid, but it's so soft, I'd think it would get beatup in daily use. I left it out in the truck, and I don't know if I feel like getting it this evening to start getting it cleaned up. Maybe I will.

It's likely aluminum. I was wondering if it was a gas cap cover or wheel cap or something for an older z06 but I cannot find anything that even closely resembles that emblem.

 

[Red Squirrel]

I'd check if it's magnetic, will at least narrow things down. Mercury will react with aluminium I believe. it will eat right through it, so that could be a way to confirm if it's that. Getting your hands on mercury might be hard though. Do thermometers even still use that?

I guess weight is a good indicator too. If it's really heavy it might be silver. Might also be lead?

 

[Shmee]

Hope it is Platinum. Also you could lick it

 

[Charmonium]

The metal's very soft and malleable. It's pretty light, but it's also pretty thin. My first thought was silver. It also seems like it could be a decorative cover on something, but I don't know what. I mentioned a snuff lid, but it's so soft, I'd think it would get beatup in daily use. I left it out in the truck, and I don't know if I feel like getting it this evening to start getting it cleaned up. Maybe I will.

It's most likely an alloy, but if you had reason to believe it's something close to pure, you could use the old Archimedes approach and measure it's displacement. There should charts that use weight and displacement to help you narrow it down.

 

[Muse]

I'd check first to see if magnetic. If it's a stainless steel or steel, there are liquid drops that can be used to check composition. Outside of that without a PMI gun or taking to a testing lab, not much you can do.

First thing I do is see if a magnet attracts it. If AL is suspected, judge its weight in proportion to volume. AL is so much lighter than any steel it's usually quite apparent.

If you suspect silver, it tarnishes black, no? AL tarnishes white.

 

[Charmonium]

If you suspect silver, it tarnishes black, no? AL tarnishes white.

The wonderful thing about Aluminum is that its oxide is the same compound as sapphire. So it's the perfect thing to use outdoors, like aluminum siding.

 

[Charmonium]

BTW, if you're going to use the magnet test, let me suggest getting an N45 neodymium magnet. It should be able to give you some pull even on an alloy that's not mostly ferrous

edit - the larger ones (more than .5" cubed) are quite capable of causing injury. So pls . . . don't get one of the 2" monsters.

 

[lxskllr]

I don't think it has any steel in it. Something about it doesn't feel like aluminum to me either, but I'm not a metalworker or anything. I don't even really care that much. It's just an interesting thing I found, and I don't want to throw something away that has value. If it did turn out to be interesting, it would probably go with my scrap precious metals, and someone will deal with it(probably throw it out :^D ) after I'm dead. I might even use it for something if I can roll the metal out smooth enough.

I don't think shininess is a solid indication of feral silver. I found an 1890(? can't quite remember) quarter in a field that was almost as shiny as the day it was minted. Took it home, put it in a tin on my dresser, and it immediately aged 135 years :^D I guess some kind of galvanic corrosion.

 

[Torn Mind]

Bubbles will form when sodium hydroxide solution makes contact with aluminum. This is hydrogen gas forming.

Phosphoric acid will also eat up the material if it is aluminum.

 

[Charmonium]

Bubbles will form when sodium hydroxide solution makes contact with aluminum. This is hydrogen gas forming.

Phosphoric acid will also eat up the material if it is aluminum.

Using acid is a good idea and the strength of the reaction might give you some clue as to composition but you'll need to do some research to know what you're looking for.

Finding the melting point might also give you some clue. Finally, you can see if it burns and if so, what colors you see - kinda like the spectroscopy idea earlier.

edit - not sure vinegar will give you much of a reaction but HCl (muriatic acid - available in hardware stores) might be one to try.

 

[Fenixgoon]

if you have a nearby metal distributor or scrap yard, ask if they have an XRF or LIBS gun and if they can give you a quick analysis. these tools will give you composition with an error of like 0.1 wt% (1 part in 1000)

edit: also, polish the surface. even 400 grit on steel, cast iron, and aluminum will look different on the surface, and the finer the polish the better the differentiation. a fresh surface will also help with the above-mentioned XRF/LIBS analysis

 

[BoomerD]

Hope it is Platinum. Also you could lick it

Indeed. Let your taste buds decide.

 

[WelshBloke]

Doesn't silver react with bleach? I have that in my head as a thing.