World of Coins

Research and reference => Numismatics => Topic started by: kansal888 on August 17, 2011, 05:39:37 PM

Title: How to determine silver content
Post by: kansal888 on August 17, 2011, 05:39:37 PM
Dear Friends

In India a Quaternary alloy having 50% silver is used to mint high denomination commemorative coins. Is it possible to crosscheck the exact silver content by some NDT method (Non Destructive Test)?

Please advice so as to how the silver content can be verified without destroying or damaging the coin

Regards
Sanjay Kansal
Title: Re: How to determine silver content
Post by: Abhay on August 18, 2011, 01:38:58 AM
Dear Sanjayji,

Just refer this topic:

http://www.worldofcoins.eu/forum/index.php/topic,8140.0.html


http://www.olympus-ims.com/en/xrf-xrd/delta-handheld/delta-alloy/

Abhay
Title: Re: How to determine silver content
Post by: UK Decimal + on August 18, 2011, 02:05:04 PM

I hadn't studied the links given above before now, but they make interesting reading.   How is use of the equipment progressing?

As an aside to the present question, when British .500 silver coins became cupro-nickel in 1947, a finer edge graining was used.   Unfortunately, when the silver content was changed from .925 to .500 during 1920, there was no such indication.

Apart from the early .500 issues (until about 1922) turning a slightly yellowish colour, there is no visual indication of the silver fineness.   After about 1922, a better alloy mix was devised.

Bill.
Title: Re: How to determine silver content
Post by: akona20 on August 18, 2011, 10:38:02 PM
Use of the equipment has been delayed due to my injury. I am hoping to have things back on track very shortly.