| 释义 |
hornstone Min.|ˈhɔːnstəʊn|
[tr. Ger. hornstein: from its appearance.]
A compact siliceous rock, resembling flint, but more brittle; chert.
1728Woodward Catal. For. Fossils 11 Rother Hornstein, i.e., Red Hornstone. 1796Kirwan Elem. Min. (ed. 2) I. 305 Hornstone differs from jaspers, often by its splintery fracture. 1816Keatinge Trav. (1817) II. 155 Here the sand-stone approaches to horn-stone; that is, assumes the rhomboidal conformation. 1833Lyell Princ. Geol. III. 370. a 1862 Thoreau Maine W. iii. (1864) 180 This variety of hornstone I have seen..in..New England, in the form of Indian arrowheads, hatchets, chisels, &c.
b. attrib., as hornstone basis, hornstone porphyry.
1796Kirwan Elem. Min. (ed. 2) I. 351 Hornstone Porphyry. Ibid. 368 [It] has for its ground a hornstone basis. |