Telling The Difference Between 50% And 80% 1967 Silver Quarters/Dimes

Archer RA I want to show you what is on. one of my mackerel dimes fins. yes letters how is that possible

hozer I use the World Coin Books. what do you mean you use this book. I see the finns on the mackerel are disconnected from the body. I wonder are they all this way.

its like this coin is plated with silver. was there any gold centennial dimes. where ever there is a little scratch it has yellow metal under the surface. see this anomaly near the mouth.

the groove are more like. the Philadelphia mint grooves. that yellow is everywhere. that would be great if this was there metal. any thoughts have agreat one.

Full destructive chemical analysis should yield trustworthy accurate results to determine if a coin is / was 50% or 80% silver.
To be honest, I am not keen on this approach.

Perhaps XRF testing (non destructive), would yield even more accurate results, but the fee for testing is not justified.
Drop ping test quite OK on melt value coins.

According to Krause, there is no difference in the value of the 1967 50% and 80% 10 Cents and 25 Cents coins, across the grades.
I cannot think why anyone would want to take a silver coin out of a 1967 mint set to test it for fineness, especially when it can be safely assumed that it is going to be 80% fine.
For these reasons, my attitude would be to just collect all of them in superior condition, without question.

thank you very much LL for that information. heres one on
e-bay. I was just wondering what this might be worth again thank you.
https://www.ebay.ca/itm/CANADA-25-C...2342241383?_

Me again. I just received a set of seven '67 dimes from an auction lot and measured each of them at the indicated location. Got the following measurements (in inches, sorry to my friends in Canada)...
0.0325, 0.0337, 0.0340, 0.0348, 0.0354, 0.0363, 0.0376

Unfortunately, except for the two at the min and max, the remaining pieces are not statistically distinguishable... they could be from either group. I realize that in any case it's a losing proposition to go through all this trouble if you're just worried about the value in silver. I was thinking more for the collector who wanted to fill out his or her collection by having one of each type. This seemed like a possibly valid way to do it.

A note to Rocky. I'm very impressed with the magnified photography. I'm sure you've posted it elsewhere, but if you wouldn't mind, please re-post the equipment or method for producing these images. As for the yellow color, I would venture that any such color is traceable to the constituent copper.

I'm curious about this series. I know it's an old post and I have just started cracking into the RCNA articles. As far as I can see the planchette these 10¢ and quarters are two different varieties. Other then an XRF is there an accurate way to find the 50-80%? The 50%(even though less silver) from what I have read is harder to come by?