Geol. Also 8–9 tuffa, 9 tufo, tupha. [a. It. tufa, tufo:—L. tōfus, tōphus: see TOPHUS; cf. TUFF sb.]
1. A generic name for porous stones, formed of pulverulent matter consolidated and often stratified. (See Note s.v. TUFF sb. 1.)
1777. G. Forster, Voy. round World, I. 586. The stone of which the statue itself is formed … being nothing but the red tufa which covers the whole island.
1789. J. Williams, Nat. Hist. Min. Kingd., II. 382. There are great quantities of the concreted substance called tufa in many parts of Scotland.
1849. Dana, Geol., iii. (1850), 241. The tufa is very friable, yielding easily to the fingers.
spec. a. Calcareous tufa: ‘a porous or vesicular carbonate of lime, generally deposited near the sources and along the courses of calcareous springs’ (Page, Geol. Terms, 1865). Cf. TUFF sb. 1 a.
1811. Pinkerton, Petralogy, I. 518, note. At Bionnay there are houses built of a calcareous tufa, containing fragments of lime-spar, limestone, and slate. Ibid., II. 374, note. This [tufo] is the Italian and classical orthography. Tufa may be reserved for depositions merely aqueous.
1839. G. Roberts, Dict. Geol., Tufa, or Calcareous Tufa..., a friable earthy deposit from calcareous springs. The more solid form is travertin.
1865. Livingstone, Zambesi, xi. 222. In the vicinity of the erupted rocks we usually meet soft calcareous tufa.
1867. Ansted, in Brande & Cox, Dict. Sc., etc., Tufa [is] a name applied in Italy to certain porous loose rocks…. Volcanic Tufa is the material under which Pompeii was buried…. Calcareous Tufa when consolidated passes into Travertine.
b. Volcanic tufa: see TUFF sb. 1 b.
1770. Hamilton, in Phil. Trans., LXI. 7. The Italians distinguish it by the name of tufa, and it is in general use for building.
1772. Nat. Hist., in Ann. Reg., 79/2. What is called here Tuffa … is the same that covers Herculaneum, and that composes most of the high grounds about Naples; it is … a mixture of small pumice stones, ashes, and fragments of lava,… hardened into a sort of stone.
1778. Phil. Trans., LXVIII. 2. The walls were … of a tuffa exactly resembling that of Naples and its environs.
1794. Sullivan, View Nat., I. 84. The … mass through which the catacombs are excavated are all indurated tufa.
1811. Pinkerton, Petralogy, II. 374. Brochant … supposes that they become volcanic tufo.
1838. Murray’s Hand Bk. N. Germ., 239/1. Composed … of tufa and scoriæ, exactly similar to that found on Vesuvius.
1862. Dana, Man. Geol., I. 685. When rain or moisture from any source descends with the cinders, the mass forms tufa,—a stratified, somewhat earthy, granular … rock, of gray, yellowish-brown, and brownish colors.
1866. Lawrence, trans. Cotta’s Rocks Class. (1878), 89. Tufa is now principally used to denote an earthy compound of volcanic products of the most various kind.
2. attrib. and Comb., as tufa cement, grotto, quarry, rock, stone, wall; tufa-like, -paved adjs.
1839. W. Chambers, Tour Holland, etc. 55/1. Andernach is an ancient walled town, and the seat of a considerable export trade in oven stones and *tufa cement.
1910. 19th Cent., Feb., 365. The piers were formed of *tufa-like Caux stone.
1905. R. Bagot, Passport, i. The steep, *tufa-paved street.
1891. Farrar, Darkn. & Dawn, xxiv. The overhanging sides of the *tufa quarry.
1820. T. S. Hughes, Trav. Sicily, II. xv. 368. Some workmen were excavating a wine vault in the *tufa-rock.
1861. J. H. Bennet, Winter Medit., I. viii. (1875), 229. The island [Capri] is of limestone—a healthier geological formation than the soft tufa rock of Naples.
1793. Trans. Soc. Arts (ed. 2), V. 222. A *Tufa stone, found on the rocky banks of the Rhine.
1894. Daily News, 22 Sept., 6/2. The columns … are generally of grey tufa-stone.
1877. J. Northcote, Catacombs, I. iii. 45. He strengthened the friable *tufa walls of some of the galleries … by … arches of brick and stone work.
