白玉質，帶黃沁。璧扁圓，材料厚實，雙面工，器中心刻花紋轉心，系用同塊材料雕琢而成，璧兩面陰刻天干、地支紋。外出廓雙龍紋，左右對稱。明代出廓璧為擬古之器。中有穿孔，可供穿系佩掛。甲、乙、丙、丁、戊、己、庚、辛、壬、癸稱天干，子、醜、寅、卯、辰、巳、午、未、申、酉、戌、亥稱地支。把十個天干與十二個地支依此配合起來，組成六十對，周而復始，叫做“甲子”或“六十花甲子”，用來表示時間順序，這是中國古代曆法的獨特創造。 Made of mellow and refined white jade with some yellow-russet markings. The bi is round and flat with the center decorated with a carved floral pattern made of the same jade material. The two sides of the bi are inscribed with the Chinese Sexagenary cycle names. Extending out of the bi are two symmetrical dragons. There is a pierced hole at the center for string tying purposes.