Problems testing silver jewelry...

I've been trying to test some unmarked and marked silver jewelry that I've had for years...trying to label things for future selling.

A few days ago I posted photos of a necklace that I thought might be platinum because it's heavier than sterling, and @Kaiserpoo translated the Chinese marks and included a link to the probable maker in Hong Kong. It tested positive for platinum, but I was using old platinum testing solution and was told old solutions lose their effectiveness, so I ordered a new bottle. However, when I tested it with the new platinum solution, the scrapings dissolved. So I took it to a jeweler who used an electronic tester which showed the necklace is solid platinum (she also did a teeny scrape on one of the links (which she later polished out) to make sure it wasn't plated, which it wasn't).

Anyway I did more research on testing solutions to figure out why my old platinum solution seemed to work and the new solution didn't. Somewhere I read that the acid can last for years if it's not used much and is kept tightly sealed. This was the first time I had used my old platinum acid.

I also read reviews on the various Amazon sellers of the testing solutions, and several buyers complained that the solutions they ordered were old and not usable. So I'm wondering if my new platinum solution is outdated and I should ask for a refund.

I'm also having difficulty interpreting results with new silver testing solution that just arrived today. When I tried it with a marked sterling silver piece of jewelry, it seemed difficult to distinguish whether the scrapings turned dark red (.925) or brown (.800) as shown in the instruction booklet. I also tried it with a few other pieces of sterling jewelry and had a hard time seeing a red color under the acid bubble.


I decided to try the same piece of sterling jewelry using brand new 18K test solution and also my old 18K solution (which I've only used a few times). Here's what happened.

So I'm thinking I should ask for a refund on the new 18k solution also--I bought it from a different seller than the platinum solution that doesn't work. Has anyone else had problems like this with metal testing solutions?

 

I would definitely ask for a refund on the Platinum solution since you have that jeweler's data. I'm still using an old testing kit, so can't comment. I always bring a piece that I know to be sterling, and do a test side by side if I have a a silver question piece, but wouldn't have helped with the Platinum. Good to know about this discrepancy and maybe others will have thoughts. Congrats on the Platinum piece, I missed that, off to check it out your post!

 

Thanks, Lucille.

 

Every time the topic of testing precious metals with acid comes up I read eagerly. I have still never tried it myself, feeling I don't know enough. However, in this particular case, why would you conclude your new 18K acid is defective because it is stronger & dissolves the silver streak in a way that the older, weaker acid does not? After all, it is meant for testing gold, a much less interactive metal than silver. Maybe hang on to your old 18K acid as a silver test.

 

The old 18k did its job. The new stuff...tested sterling as costume. Not so hot. I will say that I haven't had silver acid in the house in yoinks. It goes bad with a dirty look.

 

Evelyb30 is right that my old 18k acid did its job. I learned from others here that 18K acid is a good substitute for silver testing acid because the silver acid has such a short shelf life. Instead of dissolving a streak of silver metal, 18k acid turns it a milky blue color, which is shown in the photo above. The new 18k acid I bought isn't reacting the way it's supposed to, so it's worthless for testing silver.

Since someone told me that old 18k acid loses its effectiveness, I felt I couldn't trust the results, so that's why I bought the silver acid and figured I'd do all the silver testing over the next week before the acid goes bad. I have some old-looking Native American silver jewelry that isn't marked, Mexican silver jewelry that's marked but questionable, unmarked pieces that could be hobbyist or student-made, possibly vintage 800 silver jewelry from India, etc.

But after testing several pieces with the new silver acid for both known sterling and questionable pieces, I had such a difficult time seeing whether the colors of any of the tests were dark red or brown, I've come to the conclusion that my old 18k acid seems to be the most reliable way to test for silver, although I don't know if or how it works for 800 or 835 silver.

 

Use the unglazed back of white tile and you will see the color better.

 

I'm not sure whether a simple acid test is able to differentiate between 800, 835, 900 & 925 silver.

 

You have to be able to assess the colours and subtle differences, but even then it is not an exact science.
A side by side test with a known piece helps, as Lucille said. But helping is not exact either.

I always look at the acid drop from the side, against daylight. That gives you a better idea of the colour than looking at it straight on (from above).
As Holly said, the unglazed back of a white tile should also give you a better idea of the colour.

 

Thank you Hollyblue. I should have thought of that since it seems like such an obvious solution. I'll post photos after I find a tile.

 

Thank you, AJ, for the tip about looking at the acid drop from the side. The first couple of times I squeezed a drop on the black tile it didn't form a bubble...just spread way out beyond the scrape. So I decided to give the bottle a few good shakes (hoping it wouldn't explode), and then it formed a bubble on the stone, so I'm wondering what that means, but am anxious to try it on an unglazed white tile.

 

It does, sort of, but it takes practice and isn't totally accurate. The faster the acid reacts the purer the silver. With practice you can make a good guess about silver purity, but then the silver acid isn't that much better.

 

Thank you, @evelyb30 and others who've helped...I found an unglazed, or maybe matte glazed, whitish floor tile and a bisque trinket box to try with silver, but am getting ready for company so will post a photo of results next week.

 

I decided to start a new thread with photos. Here's a link:
https://www.antiquers.com/threads/s...arked-silver-necklaces-signed-earrings.81581/