Indurated Marle. 527 Fragments indeterminately angular, and partly flaty. Opaque, at the utmoft weakly tranflucent on the edges. . So foft as to yield to the nail. Not particularly brittle.. Eafily frangible. Not particularly heavy. Chemical Characters. It melts before the blow pipe into a greyifh black glafs; it makes a brifk effervefcence with acids. w Geognostic Situation. Occurs principally in beds in the floetz lime-ftone, and independent coal formations ; in the firft it alter* nates with beds of lime-ftone, and fometimes occurs in. nefts in it. Geographic Situations. It is found in the coal works in the vicinity of Drtfden, in thofe' of Wehrau, and in many other places where the floetz lime-ftone and coal formations occur. *3*