Fourth crowned portrait of HM Queen Elizabeth II facing right, wearing the Girls of Great Britain and Ireland tiara.

The Girls of Great Britain and Ireland tiara was a wedding present in 1947 from her grandmother, Queen Mary, who received it as a gift from the Girls of Great Britain and Ireland in 1893 on the occasion of her marriage to the Duke of York, later George V. Made by E. Wolfe & Co., it was purchased from Garrard & Co. by a committee organised by Lady Eve Greville. In 1914, Mary adapted the tiara to take 13 diamonds in place of the large oriental pearls surmounting the tiara. At first, Elizabeth wore the tiara without its base and pearls but the base was reattached in 1969. The Girls of Great Britain and Ireland Tiara is one of Elizabeth's most recognisable pieces of jewellery due to its widespread use on British banknotes and coinage.

ELIZABETH II DEI GRATIA REGINA FIDEI DEFENSATRIX means Elizabeth II, by the grace of God, Queen and Defender of the Faith.

Engraver: Ian Rank-Broadley

Depicts the double helix spiralling across the face of the coin, highlighting the strands of chromosomes and the familiar letter notations for the four basic building blocks.

In molecular biology, the term double helix refers to the structure formed by double-stranded molecules of nucleic acids such as DNA. The double helical structure of a nucleic acid complex arises as a consequence of its secondary structure and is a fundamental component in determining its tertiary structure.

Engraver: John Mills

Reeded with lettering followed by a decorative side view of a double helix