Zero silver content, they are made from bronze.
All British Florins from 1921 to 1946 inclusive, had a 50% silver content.
From 1817 until 1919, all British silver Shillings had a fineness of .925; i.e. 92.5% silver or sterling silver. From 1920 the silver content was reduced to 50%. In 1947, what were silver coins, were subsequently made from a copper/nickel alloy - no silver at all. No circulating British coin has contained any silver since 1946.
A 1921 Mexican 1 Peso coin contains 0.3856 troy ounces of silver.
A 1921 Half Dollar is 90% silver. It has a melt value of somewhere around $12. The related link below has more information.
There is no Australian 1921 Halfpenny with a spurious "E" on it. You may have a genuine oddity. A reputable coin dealer will be able to assist with verification and give a valuation.
Assuming it's a more common Morgan dollar, about $13 for its silver content
All Morgan and Peace dollars have the same silver content - 90%. The coins' nominal weight is 26.73 gm so that works out to about 24 gm of pure silver in each one.
1921 is by far the most common date for Morgan dollars. At present, it's worth just under $21 for the silver content.
There is around .77 ounces in a 1921 US silver dollar.
For the series of Morgan dollars 1921 is the most common highest mintage year. Assuming the coin is circulated and depending on grade a 1921 retails at $18.00-$22.00Read more: 1921_silver_dollar_e_pluribus_unum
That depends. If it's a 1921 Morgan, then it's a really common coin and currently worth around $22 for the silver content. If per chance it's a '21 Peace dollar, then it's worth at least $60.
Nickel silver is an alloy of copper, nickel and zinc, and it was used to make 'silver' coins that were previously made in silver or 50% silver. British coins were silver up to 1921 and 50% silver until 1946, and then they were made of nickel silver. Sterling silver is 92.5% pure silver.