A Mineral, very ponderous, and probably holding Tin. […] 'Twas part of a Squat, at Hewas-Work; not far from Polgouth, in St. Stephen's Liberty, Cornwall.
1728, J[ohn] Woodward, “Earths and Earthy Substances”, in A Catalogue of the Additional English Native Fossils, in the Collection of J. Woodward M.D., tome II, London: […] F[rancis] Fayram, […]; J[ohn] Senex, […]; and J. Osborn and T[homas] Longman, […], page 23