Geol. [f. med.L. variol-a VARIOLA + -ITE1 2. Cf. F. variolite, G. variolit.] A kind of rock embedded with spherulites which give it the appearance of being pock-marked (see quots.); esp. the diabase (diorite) of Brongniart.
1796. Kirwan, Elem. Min. (ed. 2), I. 368. Variolites. Stones that have rounded protuberances, of a different nature from the common mass of the stone.
1811. Pinkerton, Petrol., I. 133. When the crystals … assume an oval, but particularly a round shape, the rock may be aptly styled a variolite. Ibid. The stones called variolites of Durance, being pebbles rolled down by that river in Dauphiny.
1879. Rutley, Stud. Rocks, xiii. 248. Variolite is an aphanitic diabase of compact texture and greenish-grey colour, in which there occur little concretions of a paler colour, ranging up to the size of small nuts.
