In the Middle Ages the opal mines of Cernowitz, in Hungary, were very actively exploited, and at the opening of the fifteenth century more than three hundred men are said to have been employed here in the search for opals. At that time, and for many centuries after, no breath of suspicion ever tarnished the fame of the opal as not only a thing of rare beauty, but also a talisman of the first rank. We are told that blond maidens valued nothing more highly than necklaces of opals, for while they wore these ornaments their hair was sure to guard its beautiful color. The latter superstitions probably arose from the frangibility of the stone and its occasional loss of fire. From the earliest times the baleful influence of the Evil Eye has struck terror into the souls of the ignorant and superstitious. It is believed by some that the name “opal”—written “ophal” in the time of Queen Elizabeth—was derived from _ophthalmos_, the eye, or _ophthalmius_, pertaining to the eye, and that hence the foolish superstition regarding the ill luck of the opal had some connection with the belief in the Evil Eye. However, this is altogether incorrect, since the stone called _ophthalmius_ by early writers, and which seems to have been the opalus of the ancients and our opal, was believed to have a wonderfully beneficial effect upon the sight, and if it was thought to render the wearer invisible, this was only an added virtue of the stone. [Illustration: 1, 2, 3, 4, 5. Eye agates, Aleppo stones, Arabia. 6 and 7. Antique eye agates, with double zone. 8 and 9. Aleppo stones set in rings. 10 and 11. Double eye agates, Aleppo stones, Arabia. 12. Natural pebble, showing eye from Isle Royal, Lake Superior. 13 and 14. Natural agates with eye-like effect, East Indian. Had been used as votive charms. 15. Eye agate, Brazil. 16. Agate called Oriental agate, eye effect, from Brazil. 17. Ancient eye of idol, agate variety sardonyx. Had been pierced lengthwise and worn as a charm on the arm. East Indian. ]