These are distinguishable from the grey Chalk coprolites by their brownish ferruginous colour and smooth appearance.
The shapes of these ferruginous sandstones are very fantastic - tubes, hollow spheres, plates, &c., being common.
The soil is composed of red ferruginous kankar, with a stratum of clay in the more elevated parts, covered by a thin layer of vegetable mould, or by recent alluvial deposits.
The ferric hydrate is also readily deposited from ferruginous waters, often by means of organic agencies.
Cold mineral springs are at Bartfa, with alkaline ferruginous waters; Czigelka, with iodate waters; Parad, with ferruginous and sulphate springs; Koritnicza or Korytnica, with strong iron springs; and the mineral springs of Budapest.