SLATE-CLAY. 419 It occasionally contains impressions of unknown ferns and reeds. It occurs massive. It is dull, or glimmering, owing to intermixed scales °f mica. The fracture in the large is more or less perfectly slaty; in the small, earthy. The fragments are tabular. It is opaque. It is. intermediate between soft and very soft. It affords a dull streak. It is easily frangible. It adheres slightly to the tongue. It feels somewhat meagre. Specific gravity, 2.036, Karsten. Geognostic Situation. It occurs in beds in all the floetz coal-formations. It passes into claystone, sandstone, and bitumhious-shalc, a nd sometimes inclines to clay-slate. Geographic Situation. It occurs more or less abundantly in all the coal dis tricts in this island; and in other parts of the world "'here coal, and its accompanying rocks, have been par ticularly attended to. D d 2 .5. Claystone.
