A bi-metallic coin is a coin which is made using two distinct pieces of metal. In most cases this comprises of a metal disc surrounded by a ring of different colour alloy.
All British two pound coins minted for circulation since 1997 are bi-metallic. Since these are a current and common coin they are only really worth face value. There have been a number of commemorative two pound coins minted since 1997 but even these will not be worth much more than their face value.
Two pound coins minted before 1997, which use the same nickel-brass alloy as the standard pound coin, were never mass produced for circulation and these coins are often sold to collectors at a premium.
The unimetallic nickel/brass Two Pound coins were issued from 1986 to 1996 as a commemorative coin. They are legal tender and were never intended for circulation, but as a souvenir of the event that they commemorate. The bimetallic copper/zinc/nickel outer ring and copper/nickel centre were issued from 1997 to present as a circulating commemorative coin. Both types of Two Pound coins are worth Two Pounds if they have been circulated. As a collectable coin, there is no great difference in value between the coins of different years.
A bimetallic coin has two metals, usually copper and nickel.
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The current bimetallic Two Pound coin was first issued in 1997. There was a trial Two Pound coin minted in 1994, but it was not issued for general circulation. From 1986 to 1996, there were unimetallic nickel brass Two Pound coins issued as commemoratives, but these were intended to be souvenirs rather than circulating currency. There have been Two Pound coins issued irregularly for many years. Most of these were non-circulating and issued only in Royal Mint sets. Earlier Two Pound coins were issued in gold in 1820, 1823-1826, 1831, 1887, 1893, 1902, 1911, 1936 and 1937.
A 1889 gold 5 pound coin is worth 5 pounds of gold, while a 1889 2 pound gold coin is only worth 2 pounds of gold.
I suggest you get a good coin book and search for your coin in there.
An "R" stamped in the middle of the Queen's head is not part of the design feature of any coin in any year. As long as the coin is recognisable as Two Pound coin, it is worth Two Pounds.
It is a common coin, worth a pound or two if in perfect condition.
There is a one pound coin and a two pound coin but not a three pound coin.
The unimetallic commemorative British Two Pound coins issued from 1986-1996 are heavier and thicker than the later bimetallic Two Pound coins issued from 1997-present. Unimetallic Two Pound coins 28.4mm in diameter 15.98 grams in weight 3.1mm thick Bimetallic Two Pound coins 28.4mm in diameter 12 grams in weight 2.5mm thick
A Two Pence coin weighs 7.12 grams. There are 50 Two Pence coins in a Pound. One Pound worth of Two Pence coins weighs 356 grams.
If by "new" you mean a decimal coin, the Half New Penny and Half Penny coin was in circulation from 1971 to 1983. The 25 Pence (Crown) coin was only issued in 1972, 1977, 1980 and 1981 and was intended to be a commemorative rather than a circulation coin. The Five Pound Crown replaced the niche of the 25 Pence Crown in 1990. The uni-metallic Two Pound coin was issued in 1986, 1989, 1994, 1995 and 1996 and was intended to be a commemorative rather than a circulation coin. The general circulation bimetallic Two Pound coin was first issued in 1997.