This app was mentioned in 22 comments, with an average of 1.64 upvotes
Yes different countries have various gold and silver customs fees depending on where you are.
There are various articles on testing gold and silver I will do up a page myself when the authentication system is running but essentially for simple testing on the outside of the bars or coins there are cheap chemical tests you can buy which are not too effective on the fakes I previously linked to which are plated with real 24k. Another better method is the ping test on coins as demonstrated here there are already some apps which can listen and detect the various coins signatures. This is particularly good at detecting tungsten rod inserts in gold.
With an android device you can use the Bullion
test app by Timmy Brolin. It uses acoustical analysis.
https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en_US&gl=US
Bullion Test by Timmy Brolin.
https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en_US
The free version will test ASEs. Well worth a few dollars for the full version.
Ice and magnet are junk imo. A good scale and/or this app will give you much better peace of mind if you aren't familiar with the coins. I have yet to see this app fail but keep in mind it's still just one tool.
Bullion Test app by Timmy Brolin for android.
https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en_US
Calipers
https://www.amazon.com/General-Tools-141ME-Pocket-Caliper/dp/B00004T7UH
A magnifier is also useful.
Weight is fine assuming your scale is accurate. I would like more precision with the dimensions to be confident. Within 1mm on the thickness doesn't cut it. Posting a pics would be useful.
With an android device you can use the Bullion test app by Timmy Brolin. It uses acoustical analysis (quantitative ping test). A maple will sound different from an ASE because it is shaped differently. https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en_US&gl=US
You should buy the full version, but if you're too cheap you can post the peak resonant frequencies from the free version and I'll tell you if it matches the values for a maple.
Try using a ping test with the Bullion Test app.
https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en_US
I agree with the thought that alloy consistency may have been lacking back then. It also might be a good fake with slightly less than 90% gold used. Is it a key date? Could it be a numismatic fake?
Bullion Test app by Timmy Brolin. https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en_US
Use a ruler or calipers to check the dimensions. Look at the details and compare it authentic photos. Where did you buy it? Also, use grams when you weigh it.
The weight is right there. If it passed this app I'd probably consider it real. I bought this app quite a while ago and it has yet to fail me. Whether it's worth more than $18 if real? Idk but probably not much. At least you'd have some peace of mind though :)
Get the Bullion Test app by Timmy Brolin.
https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest
It has a pretty good database of common coins and shows the acoustic spectrum so you can assess coins yourself if you have a known genuine specimen for comparison.
It only works on coins. I use this app: https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest
I don't know. I'm on android. This is the app I was talking about: https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest
Which is a good reason to go for coins that can be tested with the Bullion Test Android app - https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en
Not an expert, but I imagine it could check for width, diameter, and weight. I think the risk would be if it has some kind of lead or tungsten in it.
This ping test app looks like an additional option. For 3 bucks, I'm intrigued to try it out.
https://www.youtube.com/watch?v=JkhnQ7gsChk
https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&gl=US
You can use a ping test app for mobile, for example this
https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest
I use this app: https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest
They have a free on with less coins but the paid one was $10 if I remember right.
The Bullion Test app for Android is helpful.
Get the bullion test app by Timmy Brolin. https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest
For (government/popular) bullion there's a cheaper option - Bullion Test: https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en
Somebody beat me to it. Check out the Android App "Bullion test" https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en
Download bullion test app for your phone.
https://play.google.com/store/apps/details?id=se.brolinembedded.bulliontest&hl=en_US
put en.coin.net on your saved pages of your phone. You can look up the coin by year and country. Details about coins are shown. I pay membership to support the site.