Phaistos Disc
A gold signet ring from Knossos (the Mavro Spilio ring), found in 1926, contains a Linear A inscription developed in a field defined by a spiral—similar to the Phaistos Disc. A sealing found in 1955 shows the only known parallel to sign 21 (𐇤, the "comb") of the Phaistos disc. This is considered as evidence that the Phaistos Disc is a genuine Minoan artifact.