S. Epiphani Salaminis in Cypro Episcopi: De XII. Gemmis rationalis

The work De duodecim gemmis (Περὶ τῶν δώδεκα λίθων) of Epiphanius is an exegetical treatise on the twelve gemstones on the High Priest's breastplate (Ex 28:17–20 par. 39:10–13). It is the oldest Christian book on gemstones in which Epiphanius deals with the stones according to their appearance and their healing powers, as well as their attribution to the twelve tribes from a Christian perspective. [Copies of this work, one in the Wellcome collection, are accessible in archive.org]