one of the precious stones in the breastplate of the high priest ( Exodus 28:19 ; 39:12 ), and in the foundation of the New Jerusalem ( Revelation 21:20 ). The ancients thought that this stone had the power of dispelling drunkenness in all who wore or touched it, and hence its Greek name formed from a_, "privative," and _methuo , "to get drunk." Its Jewish name, ahlamah' , was derived by the rabbins from the Hebrew word halam , "to dream," from its supposed power of causing the wearer to dream.
It is a pale-blue crystallized quartz, varying to a dark purple blue. It is found in Persia and India, also in different parts of Europe.