Garlands, ribbons, bows and hearts were typical motifs of early twentieth century jewellery. The introduction of platinum in jewellery enabled a new lightness and delicacy of design. The strength and rigidity of platinum meant that the amount of metal used in a mount could be reduced to a minimum and the metal could be worked into delicate geometrical and lace-like designs. Pearls and diamonds set in platinum in open lattice work designs, long sautoirs, and diamond plaque brooches are all typical examples of Edwardian jewellery. Around 1910 the combination of black and white was fashionable and with it the combination of onyx and diamond. Diamond pieces pinned onto black velvet ribbon became very popular. The outbreak of war brought a sudden and dramatic halt to jewellery production. Precious metals became scarce and the use of platinum, which was used in the armament industry, was forbidden in England.