20 Oct 2014
The original November 1997 launch date for the new bi-colour £2 coin was postponed until the following year, but the Royal Mint had already produced £2 coins in readiness, struck with the portrait of Her Majesty The Queen by Raphael Maklouf.
This portrait had been used on all United Kingdom circulating coins between 1985 and 1997, and features the Queen wearing a necklace. By the time the £2 coin was launched into general circulation in June 1998, a new portrait of the Queen, designed by Ian Rank-Broadley which does not feature a necklace, had been approved for use on all United Kingdom circulating coins. These 1998 £2 coins were released at the same time as those minted in 1997.
This explains why some of the £2 coins in circulation feature the new portrait and others show the earlier portrait. Since millions of the 1997 £2 coins were issued, there is no reason to believe that these coins are particularly rare.