Pignelius on Revelation (Re 21:19) says that this stone has the color of a pallid lamp, shines in the open air, but is dark in a house, cannot be cut, and has powers of attraction. The etymology of the word is not less doubtful than its meaning. Some derive it from χαλκ...
Looking for the true site of Eden in the highlands of Armenia, near the sources of the Tigris and Euphrates, and applying the names Pison and Gihon to some one or other of the rivers which spring from the same region, they have been compelled to modify the meaning of נָהָ...