174 FLINT GENUS. FIRST SUBSPECIES. Common Chalcedony. Gemeiner Calzedon.—Werner. Achates chalcedonius, Wa/l. t. i. p. 298 Calcedoine, R. d. L. t. 2. p. 143—Gemeiner chalzedon, Wid. p. 317* Common chalcedony, Kirvu. vol. x. p. 298 Chalcedon, EJlner, b. 2. f. 368. Id. Emm. b. 1. f. 151 Calcedonia, Nap. p. 183.-1.3 Calcedoine, lam. t. 2. p. 142. U' Btocb. t. 1. p. 268.—Quartz, agathc, calcedoine, Havy- External Characters. Its moft common colour is grey, of which the fol lowing varieties occur : finoke grey, blueilh grey, pearl grey, greenilh grey, and yellowilh grey. The blueilh grey palles into milk white and fmalt blue? the greenilh grey into a colour which is intermediate between grafs and apple green; the yellowilh grey pafies into honey yellow, wax yellow, and ochre yel low ; irom this into yellowilh brown, blackilh brown, and brownilh black. The two laft mentioned colours are very dark, anJ when held between the eye and the light app ear Wood red. The