CALC GENUS: Geognostic Situation. Occurs in beds along with the oldefl floetz lime-' ftone. It is frequently intermixed with ores of cop per, as copper pyrites, copper glance, variegated cop per ore, and rarely with copper green, copper azure, and native copper. It contains a great number of petrified filh, that appear to be of the fame fpecies ; a.nd they are gene rally converted into coal, and fometimes the fcale* into copper ore. From the contorted afpedl of thefe petrifa&ions, Werner is of opinion, that the filh have been fuddenly killed by an inruption, or inltafl' taneous formation of the fulphureo-metallic matter- Accompanying the filh, petrified plants are found; which appear to belong to the genus Fucus. Ufe. As it is frequently intermixed with copper ore*; j it is fometimes fmelted ; in Thuringia, very extenf> vC | works are eftablilhed for the extraction of copp ef from it. twelfth