CATALOGUE OF GEMS AND PRECIOUS STONES. 169 



During the period of the increase of the moon it was a potent love 

 charm; during the period of decrease it enabled its wearer to fortell 

 the future. Carried in the mouth it became an aid to the memory. 

 As a powder and amulet it was prescribed in case of epilepsy. (Cam- 

 illus Leonardus.) It is still used for this purpose among the Basques. 

 (Crevecoeur.) 



Onyx. — Its origin, according to the Greek legend, was due to Cupid 

 cutting the nails of the sleeping Venus with his arrow; these falling 

 into the Indus were changed to onyx. 



The stone was thought to be a powerful aphrodisiac; to increase 

 spittle in children; hasten a birth; give rise to nightmare, and stir up 

 strife. Used as an eyestone "it enters of its own accord, and if it 

 found anything within that is noxious, it drives it out and tempers 

 the hurtful and contrary humors." (Camillus Leonardus, Speculum 

 Lapidum. 1502.) 



The belief in its causing nightmare and strife was widespread. This 

 belief was explained by Beononi on the assumption that "in the onyx 

 is a demon imprisoned in the stone who wakes only of a night, causing 

 terror and disturbance to sleepers who wear it." 



Among the Persians the onyx is to-day administered as a drug for 

 the cure of epilepsy. 



Opal. — Symbolical of hope. 



The gem was in great repute as an eyestone, and was used in all 

 diseases of the eye. It partook of all the virtues of those stones 

 whose colors it showed. (Camillus Leonardus, Speculum Lapidum. 

 1502.) 



It stimulated the heart; preserves from contagious and infectious 

 airs; drives away dispondency; prevents fainting, heart disease, and 

 malignant affections. (Giov. B. Porta, Magiae Naturalis. 1561.) 



The opal was supposed to indicate the state of health of its wearer 

 by change of color, losing its brilliancy if the wearer was ill, and 

 the opposite. 



The idea that the opal is unluck}' is based on a Teutonic supersti- 

 tion, and is comparatively modern. Mention of its supposed evil 

 qualities is made in a work entitled "Art Magic; Mundane, Sub- 

 mundane, and Supermundane Spiritism," in which the opal is cred- 

 ited with being fatal to love and sowing discord between giver and 

 receiver. 



Pearl.- — Emblematic of purity, beauty, and nobility. 



Pliny states that pearls were supposed to be generated by a celes- 

 tial dew falling on the shellfish, which, in the early mornings of certain 

 seasons, left the bottom of the sea to draw in the air containing the 

 dew from which the pearls were derived, the size and quality of the 

 pearl depending upon the size of the dewdrop and the purity of the air. 



