Volltext Seite (XML)
284- FITCHSTONE FAMILY. Observations. 1. The distinct concretions distinguish this species from all the other members of the Pitchstone family : it is further characterised by its colour-suite, kind of lustre, great frangibility, and low degree of hardness. 2. Some mineralogists describe it as a variety of Obsi dian ; others as a Zeolite, under the title Volcanic Zeolite; but Werner, with more propriety, views it as a species distinct from either of these, and, from the resemblance of the most characteristic varieties to I’earl in colour, lustre, and form, names it Pearlslone. 4>. Pumice. Biinstein, Werner. Porus igneus, Wall. t. ii. p. 375.—Pumex vulcani, Pom. dc L- ' t. ii. p. 629.—Bimstein, Wid. 350.—Pumice, Kinv. vol. i- p. 415.—Bimstein, Emm. b. i. s. 350.—Pumice, Nap. p. 208. Pierre-ponce, Lam. t. ii. p. 473.—La Pierre-ponce, Brock- t. i. p. 443—Lave vitreuse pumicce, Ilavy, t. iv. p. 495.— Bimstein, Rcuss, b. ii. s. 26l. Id. Lad. b. i. s. 125. Id. Suck le th. s. 374. Id. Bert,, s. 204. Id. Mohs, b. i. s. 356. I< 1 - Ilab. s. 16.—Lave vitreuse pumicec, Lucas, p. 231 Ponce, Brong. t. i. p. 332—Bimstein, Ilaus. s. 88 Verre fibrcux, Brard, p. 448—Bimstein, Leonhard, Tabel. s. 15.—Bim- stein, Karst. Tabel. s. 36’.—Pumice, Kid, App. p. 35.—Bim- stein, Steffens, b. i. s. 37.9- Id. Iloff. b. ii. s. 213. Id. Lent, b. i. s. 439.—Bims, Oken, b. i. s. 309. This species is now divided by Karsten and Werner into three subspecies : these are, Glassy Pumice, Com mon Pumice, and Porphyritic Pumice. first
