Size mismatches within a coin "family"

[<k>]

Here I want to talk about circulation coins only. I have placed this in the numismatics board, rather than in the Coin Collecting boards, because it is about past or existing circulation coins. It is not about which ones you collect or have in your collection, though you may wish to talk about that.

A coin family consists of coins of the same shape and colour. An example of a coin was the "silver" or "white" British pre-decimal coins of the 1960s: the sixpence, shilling, florin and half crown. They were all round and "white", and the size increased in proportion with the denomination. Typically, there is more one family in a coinage system. In the particular family I mentioned, there were four coins, but in the current UK decimal system, there are no more than two coins in any one family.

In 1984 Australia issued its first circulation $1 coin. It was of a brass alloy (92% copper, 6% aluminium and 2% nickel), weighed 9g and was 25mm in diameter, with an edge thickness of 3mm.

In 1988 Australia issued its first circulation $2 coin. It was of the same brass alloy (92% copper, 6% aluminium and 2% nickel), weighed 6.6g and was 20.5mm in diameter, with an edge thickness of 2.8mm. 

Australia thereby committed one of the worst errors in modern numismatic history, because in that particular coin family (brass or "yellow"), the $2 coin is smaller than the $1 coin, so the size of the coin does not increase in proportion with its nominal face value. This is counter-intuitive and against all tradition. The Australians could have produced a larger brass coin of around 28mm, but their coinage is already considerably heavy, so they decided to go smaller. Other options could have been considered rather than another brass coin: perhaps a shaped brass coin, since bimetallic coins were not common at that time.

Do you know of any other mismatches within a modern coin family, anywhere in the world? I am talking only about circulation coins here.

 

[<k>]

Well, wouldn't you know it. The Americans got it wrong too: the dime is smaller than the nickel. No wonder Britain had to throw the USA and Australia out of the Empire.    They're just lucky we still allow them to speak our language.   

Nickel
Weight     5 g
Diameter   21.2 mm
Thickness    2 mm

Dime
Weight     2.3 g
Diameter   17.9 mm
Thickness   1.4 mm

Quarter
Weight     5.7 g
Diameter   24.3 mm
Thickness   1.8 mm

Half dollar
Weight     11.3 g
Diameter   30.6 mm
Thickness   2.2 mm

[Alan71]

Canada's coins are similar (or same) specifications to those of the US, so their ten cents is also smaller and lighter than their five cents.  Someone on here explained it recently, something to do with their "dime" (10c) being silver for a long time, whereas their "nickel" (5c) was never in silver.

[<k>]

Strange. So silver and copper-nickel (or nickel) are regarded as different "colours" - or shades - and are not lumped together under the blanket term "white", as they would be in the UK and probably most other countries.

[SandyGuyUK]

This was presumably why the French 10 Franc coin in nickel that replaced the bronze larger coin never caught on as it was smaller than the other coins in that family - ie half franc, 1, 2 and 5 franc coins.  And perhaps the same as the Susan B Anthony dollar coin in the US??

[<k>]

I liked the nickel brass 10 francs - it had a very 1970s "jazz fusion" sort of design.    Why did they change it? It was a nice size at 26 mm, but maybe a bit heavy at 10 g.  The nickel version was 21 mm and 6.5 g - a similar thickness at around 2.5 mm, though.

[<k>]

And perhaps the same as the Susan B Anthony dollar coin in the US??

26.4 mm in diameter - smaller than the half dollar. However, though it was round, it had an polygonal inner rim. The woman with the bun looked just too ordinary for a coin, though. It could have been the grandma out of "The Beverly Hillbillies". 

[Prosit]

Susan B Anthony was put on there for political reasons and was never popular with the public or collectors.
Dollar coin have never been universally popular since I guess pre-1935.

The Anthony dollar was disliked (so they say) because it was too much like a quarter.
I think it was just because people had almost 45 years of no dollar coins, only notes and people resist change.

Dale

26.4 mm in diameter - smaller than the half dollar. However, though it was round, it had an polygonal inner rim. The woman with the bun looked just too ordinary for a coin, though. It could have been the grandma out of "The Beverly Hillbillies". 

[FosseWay]

Strange. So silver and copper-nickel (or nickel) are regarded as different "colours" - or shades - and are not lumped together under the blanket term "white", as they would be in the UK and probably most other countries.

This is because historically the US, Canada and some other American countries had (cupro-)nickel coins alongside silver ones at the same time. Because silver is worth more, it stands to reason that higher denominations in silver could be considerably smaller than lower ones in base metal. During the 20th century, the loss of the requirement to link currencies to weights in silver and gold, plus general economic exigencies, led to the abandonment of silver as a circulation coinage metal in the US etc. But for reasons of tradition, practicality or sheer inertia, no-one got round to making the coins more logical in their relationship to each other when they are all substantially made of the same stuff.

The UK and the places it exported its coinage system to did not have this problem. Silver-coloured coins were either all made of silver, or none of them were. It therefore stood to reason that they increased in size with increasing value. Other levels of value - lower and higher - were expressed in metals of notably different colours.

There are analogies to the US situation in e.g. Belgium, where the pre-WW1 cupro-nickel 5, 10 and 25 centime coins were much larger in proportion to their face value than the silver franc and higher denomination. Between the wars, silver was progressively abandoned, but the coins' relationship to each other didn't keep up, such that the immediately pre-WW2 25 centimes was in cupro-nickel, 26 mm, 6.5 g, while the 5 franc coin, worth 20 times more, was 25.2 mm, slightly heavier at 9 g, but still only made of nickel.

[<k>]

Good explanation. I believe there were still some semi-silver coins circulating in the 1960s, alongside copper-nickel coins of the same denominations.

[<k>]

The Anthony dollar was disliked (so they say) because it was too much like a quarter.
I think it was just because people had almost 45 years of no dollar coins, only notes and people resist change.

Dale

Yes, where an equivalent note is available, people tend to cling to it. The Manx and the Jersey and Guernsey islanders still prefer their notes to the 1 and 2 pound coins.

[FosseWay]

Good explanation. I believe there were still some semi-silver coins circulating in the 1960s, along copper-nickel coins of the same denominations.

I presume you mean in the UK. Yes - I got the occasional silver shilling in change right up to when the size changed. And I've had several silver 1 krona coins in change in Sweden. (Sweden dropped silver in 1968, and, rather like the UK, the pre- and post-change coins carry the same designs.)

My point is not that coins of substantially the same specifications change from silver to base metal - in this case, the size relationship across the series is maintained even if the coins in circulation are of both types. It's more when the coinage is designed as having two levels of base metal, one of which is silver-coloured, as well as a silver level. If the silver level then gets abandoned and replaced like-for-like with something that looks similar but isn't silver, there will be a logic clash with the existing silver-coloured small change.

Germany after the reform of 1923 avoided this, even though the precious metal coinage was successively debased and eventually abandoned altogether, by having red and brass-coloured coins at the low end, not red and white. The brass (later zinc) retained a clear difference from the "silver", regardless of what the "silver" was actually made of.

[<k>]

Yes, that makes sense. I did of course mean the UK.

Must have thought I was still in the UK board.

I'm still sitting in the same chair, though.

Amazing, the wonders of the internet. 

[Finn235]

The US issued a half dime until 1873; the "nickel" was introduced in 1866 because the war-torn country was still clinging to their silver. Before that, the "family" of US silver made almost perfect sense.

The big caveat there is the 3 cent "trime". Originally in .750 silver, it didn't have a very clear mark of value (III set in a large C) and only 1.5mm smaller than the half dime. It obviously wasn't very popular, so the Mint introduced another 3 cent in cupronickel in 1865, this time almost exactly the size of a dime. Before they started massively accumulating numismatic value, it wasn't all that uncommon for people to stuff dime rolls with "trimes".

There is of course also the 1875 20 cent piece or "double dime" that had the same design as the 25 cent piece  and was only 2.3mm smaller.

[dheer]

Not sure if you need the metal same as well

India had a small 25 paise coin in cupronickel. However the 10 paise and 20 paise were quite big with metal as aluminium