schaalsteinschalsteinn.

1804 R. Jameson Syst. Mineral. I. 519 (heading) Schaalstein.—Werner.

1804 R. Jameson Syst. Mineral. I. 520 It is named schaalstone, which in German intimates that it is composed of lamellar distinct concretions. I have not been able to find any English word synonymous to the German, so that I am under the necessity of adopting it.

1819 W. Phillips Elem. Introd. Mineral. (ed. 2) Index 300/1 Schaallstein.

1836 T. Thomson Outl. Mineral. I. 129 Bisilicate of Lime. Table spar, schaalstein, grammite, wollastonite of Hauy.

1866 P. H. Lawrence tr. B. von Cotta Rocks Classified ii. iv. 311 Some part at least of what has been called schalstein belongs to the tufa formation.

1879 F. Rutley Stud. Rocks xiii. 248 Schalstein is, according to Gümbel, a tuff, or sedimentary deposit, the material for which has been derived from ‘diabase-eruptions’.

1882 A. Geikie Text-bk. Geol. 165 Schalstein.—Under this name German petrographers have placed a variety of rocks which consist of green, grey, red, or mottled diabase-tuff impregnated with carbonate of lime and mixed with calcareous and argillaceous mud.

1897 A. Geikie Anc. Volcanoes Brit. II. xxix. 36 Some layers of this tuff assume a finely foliated appearance by the development of pale leek-green folia, which show slickensided surfaces parallel with the bedding. The rock then presents one of the usual appearances of schalstein.

1909 W. A. E. Ussher et al. Geol. Country around Bodmin & St. Austell vi. 44 North of Bury Down..the Middle Devonian Slates are associated with schalsteins.

1974 E. Lehmann in G. C. Amstutz Spilites & Spilitic Rocks 23 In the Lahn syncline..of Western Germany, the central rock complex, of upper Middle Devonian and lower Upper Devonian age, consists of so-called ‘schalstein’. Any consistency, however, suggested by that old miner's term, is not reflected in the petrographic character of the rock.