At the request of Diodorus, bishop of Tyre, Epiphanius of Salamis produced this exegetical treatise on the gemstones in the High Priest's breastplate. The oldest Christian work on gemstones, the the author deals with the stones according to their appearance and their medical benefit as well as their attribution to the twelve tribes based on Christian exegesis. Only extracts of this work are preserved in Greek. This volume provides the important – but hereto unconsidered – Armenian text with a German translation and commentarial annotations, as well as an English introduction.