Purple Gold

Purple gold — sometimes called amethyst gold — is one of the rarest and most unusual gold alloys in jewellery. Unlike standard gold alloys that achieve colour by mixing gold with copper (rose gold) or palladium (white gold), purple gold is created by combining gold with aluminium in a precise ratio, typically around 79% gold to 21% aluminium. The result is a distinctive deep violet metal that sits at 18 carats by composition. Browse gold and platinum jewellers in Hatton Garden who work with rare alloys.

The unusual colour comes from the intermetallic compound formed between gold and aluminium — a compound called AuAl2, which has a distinctly purple crystalline structure. This compound is brittle by nature, which means purple gold cannot be used in solid structural pieces the way yellow or white gold can. Instead, it is typically set as an inlay, a decorative element, or a cabochon-style inclusion within a ring, pendant or brooch that uses another metal as the structural base.

Because of its manufacturing complexity and brittleness, purple gold jewellery is rare and commands a significant premium. It is most commonly seen in bespoke or high jewellery commissions rather than mass-produced pieces. In Hatton Garden, a small number of goldsmiths with specialist knowledge of unusual alloys can work with purple gold — it is not a material found in standard stock. If you are interested in a commission involving purple gold, it is worth speaking directly with bespoke jewellery designers in Hatton Garden who have experience with rare alloys.

Purple gold price varies significantly based on the complexity of the commission and the quantity used. As a guide, pieces incorporating purple gold inlay typically start at several hundred pounds and rise steeply for complex designs. The rarity of the material and the skill required to work with it — combined with its striking appearance — make purple gold one of the most distinctive choices available in fine jewellery today.