10 Pounds - Elizabeth II 5th portrait, 1/10 oz Fine Gold

The .9999 fine standard used here — sometimes called "four nines" — became the Royal Mint's benchmark for bullion gold in the modern era, driven partly by competitive pressure from the Canadian Maple Leaf, which had pioneered that purity level decades earlier. The guilloche sunburst finish applied to the field is a laser-activated security feature introduced to deter counterfeiting of the smaller fractional issues, which by virtue of their lower entry price attract more forgery attempts than the full-sovereign weight coins.

Jody Clark's fifth portrait of Elizabeth II, adopted across circulating and bullion coinage from 2015, was the first royal effigy designed by an in-house Royal Mint engraver in over a century.