The lower section of the four walls of the St. Wenceslas Chapel in St. Vitus' Cathedral at the Prague Castle is decorated with twelve paintings of the Redemption Story, including panels of polished semi-precious stones - amethyst, jasper and chrysoprase. We base an examination of the symbolism of these precious stones upon medieval biblical commentaries to the Scripture, particularly commentaries on the Revelation of St. John. In the fourth chapter (Rev. 4,3) St. John describes a vision of God's Majesty resembling jasper and sardius surrounded by the emerald rainbow; in the twenty-first chapter (Rev. 21, 19-21) he describes the appearance of Heavenly Jerusalem, whose city foundations are adorned with twelve precious stones. Green stones (jasper and emerald), linked to vegetation on account of their colour, are symbols of faith, Christ and the desire for eternal life; the combination with red makes them symbols of Christ's divine nature. The red stones are identified with Christ and are symbols of his suffering, his human nature. Purple was always the colour of royal garment, and so amethyst too becomes a symbol of the Heavenly Kingdom.

The St. Wenceslas Chapel has always been taken as an image of the Heavenly Jerusalem. This hypothesis is supported by the arrangement of the chapel, its dedication to St. John the Evangelist, and the symbolism of the precious stone with which it is decorated. However, in the chapel as a whole the dominant colours are the green and red; this colour combination is most often connected with Christ and his two natures, human and divine. In combination with the passion cycle and with the motif of the cross which appears in the chapel in countless variations, they suggest the possibility of a different conception of the chapel, conceived as a commemoration and celebration of Christ's sacrifice and martyrdom in general, conceived as a reliquary. This conception of the chapel is supported also by its dedication to St. Wenceslas, patron of the Czech Lands and Czech martyr.