chert
(tʃɜːt)
Also 7–8 chirt.
[App. a local term, which has been taken into geological use. Origin not ascertained. Prof. Skeat compares Kentish place-names like Brasted Chart; but this chart is explained by Parish and Shaw as ‘a rough common overrun with gorse, broom, bracken, etc.’, whence charty rough uncultivated (land).]
1. A form of amorphous silica found in several varieties, e.g. flint.
| 1679 Plot Staffordsh. (1686) 124 A sort of black Chalk found between the beds of Chirts, and the beds of gray Marble. 1729 Martyn in Phil. Trans. XXXVI. 30 Chert, this is a kind of Flint..called so, when it is found in thin Strata. 1734 Phil. Trans. (abridged) VI. ii. 192 The Strata of Chert are often four Yards thick. 1747 Hooson Miner's Dict. E iv b, Attended with small Chirts, Cauks, etc. according to the Nature of the Vein. 1813 Bakewell Introd. Geol. (1815) 211 Seams of siliceous earth, called chert, which nearly resembles flint. 1853 Lyell Princ. Geol., Gloss. Chert, A gradual passage from chert to limestone is not uncommon. 1868 Dana Min. (1880) 195. |
2. attrib. and in comb.
| 1863 Reader 14 Feb., Flint and chert implements were found in much lower positions. 1865 Daily Tel. 3 Nov. 5/4 The ‘mill-room’ in which huge chertstones are shoved round by iron arms. 1888 Jrnl. Derbysh. Archæol. Soc., The skeleton lay upon a bed of chert-fragments. |