Chapter 7: On green gems

8. Certain believe that the jasper gives both attractiveness and safety to its wearers, but to believe this is a sign not of faith but of superstition.

9. The topaz is of the green sort and it glitters with every color. It was found first in an island of Arabia in which Troglodyte pirates, worn out with hunger and storm, discovered it when they pulled the roots of herbs. This island was sought for afterward, and was at length found by seamen, being all covered with clouds. And on this account the place and the gem received the name from cause. For τοπάζειν in the Troglodyte language denotes seeking.

12. Heliotropium[359] ... receives the sun-light after the manner of a looking-glass, and reveals the eclipses of the sun, showing the moon passing under. In the case of this gem there is also a most manifest proof of the shamelessness of the magi, because they say its wearer is not visible if he takes an infusion of the plant heliotrope and in addition utters certain charms.

[359] Striped jasper.