17 6 COPPER. 18. Muriate of Copper or Atacamitd. Salzkupfererz, fVerner. This species is divided into two subspecies, viz. Com pact and Arenaceous. First Subspecies. Compact Muriate of Copper. Festes Salzkupfererz, Werner. Cuivre muriate massif, Brong. t. ii. p. 228—Gemeines Salz kupfererz, Karsten, Tabel. s. 64.—Cuivre muriate, Hatty, Tabl. p. 89—Blattricher & Strabliger Smaragdochalzit, Haus. Handbuch, b. iif. s. 1039.—Muriate of Copper, Aikin, p. 34, External Characters. Its colours are emerald-green, leek-green, olive-green^ and blackish-green. It occurs massive, disseminated, in crusts, or investing; and in short needle-shaped crystals, of the following forms : 1. Oblique four-sided prism, betelled on the extremi ties, the bevelling planes set on the acute lateral edges. 2. The preceding figure, in which the acuter lateral edges are deeply truncated, thus forming a six- sided prism. Internally it is shining and glistening, inclining to re sinous. The