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.

Engraver: Ian Rank-Broadley

Depicts volunteers in a variety of volunteering activities (fire-fighting, surf life-saving etc.) around the rim. At centre, the denomination 50. Around that and within the volunteer figures, inscription reading AUSTRALIA'S VOLUNTEERS.

Volunteering is generally considered an altruistic activity where an individual or group provides services for no financial gain "to benefit another person, group or organization". Volunteering is also renowned for skill development and is often intended to promote goodness or to improve human quality of life. Volunteering may have positive benefits for the volunteer as well as for the person or community served. It is also intended to make contacts for possible employment. Many volunteers are specifically trained in the areas they work, such as medicine, education, or emergency rescue. Others serve on an as-needed basis, such as in response to a natural disaster.