Is acid testing safe? What precautions should I take?

Hello everyone!

So about a week ago I went on Amazon and bought a silver/gold/platinum acid testing kit because it was pretty cheap and I wanted a way to definitively identify real vs fake precious metals.

However when it arrived there were no instructions or even safety warnings of any kind in the package except for a little warning not to have it around children and some advice on what to do if it gets swallowed or in the eyes. That kind of stuff.

But it doesn’t say anything about how to use the product safely.

What precautions do I need to take when doing acid testing on precious metals? Or do any need to be taken?

If anyone could advise me on this issue I would appreciate it.

Thanks!

 

Log in or Sign up to hide this ad.

Use gloves

 

Oh does the acid burn skin?

 

Just a drop . use gloves .

 

Careful not to accidentally damage a coin. Regular hum dum stuff its fine, but i'd say try and get ID on coin first. Last thing you want to do is diminish the value of something awesome accidentally.

 

Oh trust me I know better than that.

The only time I would use acid would be on bullion and even then only if it seemed suspicious to me. Like if it didn’t look or feel right.

But I would never put acid on any coin.(except the Silver Eagle I tested with )

 

How to use a gold test kit 10k 14k 18k 22k 24k/ HD shown how! - YouTube

Use gloves when using any chemical.

 

Good Video!

 

Use gloves and also have some acid neutralizer available. You can purchase a bottle for cheap or make your own with baking soda and water. Do not leave the bottles open for long periods of time as it is bad to inhale.

other tips:

Different stones are available. Some are more coarse than others. I like this because it allows you to get below platings that can be thick and deceiving. It does also take off more metal which leaves more of a mark, so some prefer softer stones if they are going to be reselling the items instead of melting them.

I would suggest using 14k acid to test 10k. We do it at our shop because 10k is often too weak to eat through gold filled items, leading to a false positive. The 10k should fade slightly with 14k acid but not disappear.

Use 22k acid to clean the stone. cover the entire stone and leave it for several minutes. Then rinse it and cover it in 10k and repeat. The 10k neutralizes the 22k acid to prevent it from messing up future tests.

 

From a chemistry hobbyist who's worked with these acids, and had a fair number of mishaps, and tends to be clumsy:

These acids are very powerful and dangerous, but you're going to be using very small quantities.

If you get the acid on your skin, it will leave a burn. Flush with cold water for a long time -- standard advice is multiple minutes, but I was never that patient. You'll likely get a yellow spot, or a black spot if the acid's already dissolved some silver, and it will turn into a blister. But if you're only using a drop or two at a time (as you're supposed to), it'll be a very small one.

If you get it in your eyes, standard advice is to flush with running water for 30 minutes, while you contemplate your life choices. You'll be spending lots of quality time with doctors.

Fumes from these acids are very bad for you, but again, working with a drop at a time the hazard is minimal. Leaving the bottles open is bad, as @CommemHalfScrub said -- bad for you, bad for any metal or paper that's around the vapors, and bad for the acids, which will lose their potency more quickly. Seal the cap tightly after each use.

To dispose of residues, flush off the stone with plenty of water. It's fine to let it run down the sink; it'll be far too dilute to cause any harm. I'll defer to @CommemHalfScrub on cleaning procedures for the stone, as I've only used mine a few times.

 

I don't think it is necessary to test bullion with acid unless it is not pure and is very unusual. To determine if a piece of bullion is genuine I rely on its weight and its specifications.

A fake silver bar will either be the correct size but about 20% lighter than it should be, or it will be the correct weight but about 20% larger than it should be. I'd avoid purchasing bullion branded from companies you are unfamiliar with, and if in doubt weigh the item and question its size. For government bullion you can use a pair of calipers to determine its size and compare that with listed specs online, along with checking its weight.

 

I'm curious about this. I've seen fake silver items that were silver-plated iron, and they'd be a bit more than 20% light, but I'd catch them with a magnet before I bothered weighing them. Silver-plated copper would be about 15% light, right?

I also assume that you mostly encounter smaller bars (one to ten ounces). For a hundred-ounce bar or kilos, would you start to worry about lead or tungsten plugs to bring up their density? Or at that size would you just drill it?

 

Good question. I learned a lot.

 

Thanks for the education everyone. Very good question thanks for posting it.

 

You’re saying that I shouldn’t dunk my bare hand into concentrated lie with a small cut on my finger?

(I’m an absolute idiot)

 

That’s not always true. It is possible to make a fake silver bar/round/coin with the correct weight & dimensions by using alloys of various metals both heavier (like tungsten) and lighter (like nickel) in order to get the weight right.

I mean generic bullion is generic bullion and if it doesn’t have any sort of premium I don’t think there is any harm in a small acid spot.

Heck if anything it shows the dealer you might sell to in the future that it’s real silver so he doesn’t have to test it again.

 

HI. If you are doing testing in your house, make sure you do it near your sink. If you have a mishap, bottle leaks or spills (yes the top of the bottle with the dropper can fail and spill the contents) you can flush with baking soda and water to neutralize the surface before the acid eats into you or the surface you are working on. If you wear gloves, make sure they are acid resistant and not cotton or any material. The acid would just seep through the material and burn your skin.
US Law mandates (National Gold and Silver Stamping Act, 1905 with amendments) that gold jewelry sold by a vendor MUST be stamped with a marking that indicates the items karat number. The Law also states the real purity of the piece can deviate by up to 0.5 karats from the karat weight. PLUMB Gold must be a true Karat and is marked with a P. 14KP must be a true 14K and not 13.5K as permitted. That means the clasp and the piece itself MUST be marked. Before testing, look for the gold karat marks first. Look for a manufacturer. Be wary of items marked "made in China". I have a large collection of counterfeit jewelry, coins and bullion made in China.
Don't clean your stone on your backpack, shirt, pants, any material. Wash the stone to neutralize the acid. I have two stones and rub them together to remove the old gold scratches. Follow the advice given by members here to be cautious. Those acids burn. Don't breathe the fumes. Neutralize with baking soda and water or at least plenty of water. Don't test coins. Use known counterfeit detection methods first on a coin. As you study, you will learn die characteristics of coins and the means to identify a genuine coin by the characteristics of the die used to mint that particular variety of coin. Learn what RGP, GF, HGE, and other initials mean. Be a careful, happy silver and gold tester. Enjoy the coin collecting hobby and the Bullion end of the hobby.

 

All excellent advice. I'll admit that I'm a bit cavalier when it comes to safety equipment if I'm dispensing from a dropper bottle, but for a bottle I don't trust, I'll err on the side of caution. When I'm pouring corrosives, I use gloves and eye protection every time, and a shield if I'm doing something that's likely to splatter.

 

Good advice! Thanks!

But I just want to mention that the US Laws requiring gold/silver to be marked wouldn’t really help because a counterfeiter could just stamp “.925 silver” or “22K gold” on something even if it has zero gold or silver.

What about ventilation? Are there fumes that require it to be done in a well ventilated space?

 

What would happen if someone got the 22K gold testing solution in their eyes?

It left a huge black scar in my Silver Eagle so I can only imagine what it would do if it got in someone’s eyes.

Im surprised there is no license required to buy acids.