1920
Ag 92.5%, Cu 7.5% OR
Ag 50%, Cu 40%, Ni 10% OR
Ag 50%, Cu 45%, Mn 5%
The composition of all the silver coins was debased in 1920 from 92.5% sterling silver to 50% silver. Initially the alloy used was Ag 50%, Cu 40%, Ni 10%, but this was not found to be satisfactory, and consequently some coins from 1920 have manganese in their alloy. Ag 50%, Cu 50% was tried briefly and found to be even worse, and finally Ag 50%, Cu 40%, Ni 5%, Zn 5% was settled on. This alloy saw the coinage through to the final removal of silver in 1946.
Both sterling and 50% silver threepences have been found dated 1920, and those with better trained ears than I can tell from the ring which is which. I can't, and I was never that comfortable with dropping coins on a hard surface in order to listen to the ring, so this a variety that I never attempted to include.
He's a great specialist in UK coins, and he could NOT see any differences! So I think we'll have to live with that?
Cita: "Sjoelund"From Declan's web site: http://declanmageecoins.co.uk/G53.html#1920
1920
Ag 92.5%, Cu 7.5% OR
Ag 50%, Cu 40%, Ni 10% OR
Ag 50%, Cu 45%, Mn 5%
The composition of all the silver coins was debased in 1920 from 92.5% sterling silver to 50% silver. Initially the alloy used was Ag 50%, Cu 40%, Ni 10%, but this was not found to be satisfactory, and consequently some coins from 1920 have manganese in their alloy. Ag 50%, Cu 50% was tried briefly and found to be even worse, and finally Ag 50%, Cu 40%, Ni 5%, Zn 5% was settled on. This alloy saw the coinage through to the final removal of silver in 1946.
Both sterling and 50% silver threepences have been found dated 1920, and those with better trained ears than I can tell from the ring which is which. I can't, and I was never that comfortable with dropping coins on a hard surface in order to listen to the ring, so this a variety that I never attempted to include.
He's a great specialist in UK coins, and he could NOT see any differences! So I think we'll have to live with that?
You would still need one of each coin to try and distinguish between the two by dropping them on the floor. Many thanks for that.
Cita: "yvon"A simple XRF-test will tell immediately and exactly which is which.
Sadly I don’t have such a machine and I probably won’t be getting one anytime soon... admittedly I’m seriously lacking in the coin-related equipment department. I have less than 10 flips for my entire collection and I don’t have any gloves, a caliper, a microscope or even a scale.
Cita: "yvon"A simple XRF-test will tell immediately and exactly which is which.
Sadly I don’t have such a machine and I probably won’t be getting one anytime soon... admittedly I’m seriously lacking in the coin-related equipment department. I have less than 10 flips for my entire collection and I don’t have any gloves, a caliper, a microscope or even a scale.
Perhaps it is possible to carefully measure a difference in density?
Examples can be found in the documentation of numista. Often works for me, using a sensitive balance, 3 digit behind the komma (very cheap on internet).
