The most valuable New Zealand Halfcrown coins in absolute mint uncirculated condition are -
1944 - $2,000 NZD
1935 - $1,500 NZD
1933 - $950 NZD
1934 - $950 NZD
But any mint uncirculated Halfcrown from 1933 to 1961 is likely to get $100 NZD or more.
Circulated Halfcrowns in average condition from 1933 to 1946 are likely to get anything from $15 to $30 NZD.
It is fairly easy. Apart from the dimensions, they are nothing alike. The British coin has GEORGIVS VI D : G : BR : OMN : REX on the front. The New Zealand coin has GEORGE VI KING EMPEROR on the front. British coins do not have the country name on them. The New Zealand coin has NEW ZEALAND on the reverse.
With the possible exception of "Traders Tokens", there were no New Zealand coins minted prior to 1933. Any coins circulating in New Zealand prior to 1933 would have been mostly British coins and some Australian coins.
Currently there would be the new 10, 20 and 50 cent coins and the 1 and 2 Dollar coins. The 1 and 2 cent coins were demonetised on the 30th of April, 1990 and the 5 cent coin was also withdrawn and demonetised on the 1st of November, 2006. The 1, 2 and 5 cents coins are no longer considered legal tender. Since the 31st of July, 2006, the Reserve Bank of New Zealand began introducing a smaller, lighter coin to replace the existing 10, 20 and 50 cent coins. The new 10, 20 and 50 cent coins are made of plated steel. The 10 cent coin has a copper appearance and the 20 and 50 cent coins have a silver appearance. The 1 and 2 Dollar coins are made of aluminium-bronze and have a gold appearance and remain unchanged from the pre-2006 design. The 5 cent coin was withdrawn from circulation at the same time and the old 5, 10, 20 and 50 cent coins are no longer legal tender, although they are redeemable for face value at the Reserve Bank of New Zealand. There is a range of non-circulating $5, $10, $20 and $150 coins that would be considered legal tender, but because their actual value is significantly greater than their face value, only a fool would use them.
There are a few sunken treasures that have been found and many are considered extremely valuable. One of the most valuable treasures found in 2007 was a colonial era shipwreck where Tampa divers discovered about 17 tons of gold and silver coins.
It should be noted that the "rarest" coin is not necessarily the same thing as the "most valuable" coin. The New Zealand 1935 Crown (Five Shillings)(Waitangi) is New Zealands rarest coin and possibly the most valuable general circulation coin, in this case. There were 660 general circulation coins minted and 468 Proof coins minted. There are quite a few New Zealand coins with various minting errors and other little peculiarities, but known quantities of these usually number in the thousands.
There were no New Zealand Halfcrown coins minted from 1954 to 1960 inclusive.
There were no New Zealand Florin coins minted from 1954 to 1960 inclusive. There were no New Zealand Halfcrown coins minted from 1954 to 1960 inclusive.
The most valuable New Zealand Halfcrown coins are the 1935 and 1944 coins in unciruclated condition. Circulated coins in good condition from 1933 to 1946 will usually attract a higher proce than those from 1947 onwards.
The New Zealand Halfcrown coin was first minted in 1933 and last minted in 1965. There were no New Zealand Halfcrown coins minted in 1936, 1938, 1939, 1952, 1954 to 1960, and 1964. The fewest coins were minted in the following years - 1961 - 80,000 1940 - 100,800 1953 - 127,000 1944 - 180,000 It is difficult to say which is the rarest coin, since nobody knows how many there are tucked away in collections.
There were 1,710,946 1892 British Halfcrown coins minted.
The smallest mintage of New Zealand predecimal general circulation coins was the 1961 Halfcrown with only 80,000 minted. The smallest mintage of New Zealand decimal general circulation coins was the 1997 Two Dollar coin with only 1,008,000 minted.
Halfcrown coins were never minted in Australia.
No. There were no Proof Halfcrown coins minted from 1840 to 1849 inclusive.
There were no British Halfcrown coins minted from 1865 to 1873 inclusive.
There were no British Halfcrown coins minted from 1752 to 1815 inclusive.
Assuming you refer to 20th century British general circulation Halfcrown coins, none are currently rated as rare. The 1927, 1937 and 1950 "Matt Proof FDC" coins are considered to be of the highest rarity. The 1952 coin is unique, there was only one made.
The first New Zealand coins were issued in 1933 and included the Threepence, Sixpence, Shilling, Florin and Halfcrown coins. The Penny and Halfpenny were first issued in 1940. Did not have much much luck finding any pictures.