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36 Calcareous Genus. fpecimen, Leite, O. 1254, which is of a beauti- ful bluilh grey colour; and.fome conchoidal, and exceeding minutely foliated, as the fpecimen in Lelke, S. 349. ( ■ 3d Family. Foliated and fparry. Spars*. jftvariety. Common Spar. Its nioft ufual colour is white or greyilh white, alfo yeUovvifh or reddifh white, more rarely olive or leek green, honey or ochre yellow, or flefli, or brownilh, or purplilh red ; ftill more rarely brown, or blüilh grey, ör greyilh black. It occurs both amorphous, cellular, flalaftitic, kidneyform, globular, or interfperfed through, or pervading in veins, other mineral fubftances, or invefting them, or filling their cavities; or cryftallized in various forms; for a minuter de- feription of which we muft refer to Mr. Rome de Lille: the moft general are the rhomboidal, but frequently we find them cryftallized in hex- agonal prifms, terminated by a pyramid oflen at one end, rarely at both, and fometimes at nei- ther. The angles of the pyramid never corre- fpond with thofe of the prifm, which dirtinguifhes them from quartzy cryftals: the pyramids lome^ times relemble the head of a nail. Very fre quently fpars occur in the form of a dog’s tooth, often in t hat of leaves, Scc. Its luftre 3,2, never o or 1, but when either decompofing or debafed by forcign ingredients. Its tranfparency 2, 3, 4, l, if of the amoy- phous kind 2. 1,5. r, * Wiih 11s the term ffar, without addition, always denote» calcartaus J]>ar, Its