Estudio del magnifico escarabeo de amatista del tesoro de Aliseda, Caceres. Es un escarabeo excepcional por sus 31 mm de longitud y por su calidad. Parece ser un escarabeo egipcio del Imperio Medio o Nuevo labrado en una amatista de Wadi el-Hudi, pero el sello fue tallado en la region sirio-fenicia en el siglo VII a.C. y montado en Hispania, probablemente en Gadir, a juzgar por su engaste. Sus excepcionales caracteristicas plantean que se trate de un sello regio, conforme confirma su aparicion en el Tesoro de Aliseda.Palabras clave: Escarabeo egipcio, Escarabeo sirio-fenicio, Escarabeo de amatista, Orfebreria tartesia, Tesoro de Aliseda.Abstract Analysis of the amethyst scarab from the Tartessian treasure of Aliseda, Caceres, Spain. It is an exceptional scarab by its quality and 31 mm length. It seems an Egyptian scarab carved in an amethyst of Wadi el-Hudi of the Middle or of the New Kingdom, but its seal was carved into the Syrian-Phoenician area in the VII century B.C. and was mounted in Iberia, probably in Gades, judging by its setting. Its outstanding features allow supposing that it was a royal seal, as confirms their appearance at the Tartessian Treasury of Aliseda.Keywords: Egyptian scarab, Syrian-Phoenician scarab, Amethyst scarab, Tartessian jewlery, Treasury of Aliseda.