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of a ſandy, as Chryſocolla and the Lapis Armenus; and others as it were of Aſhes, as [1]Sandarach, Orpiment, and others of that Kind.
- ↑ Sandarach and Orpiment are alſo two Subſtances of the ſame Nature and Texture, differing in Colour, like the Ochre and Reddle; and, in like manner, the yellow will become red by burning.
Orpiment is the Ἀῤῥενικὸν of the antient, and Ἀρσενικὸν of the later Greeks. The Arabians call it Zarnich Asfar: It is a very beautiful Subſtance, compoſed of large Flakes, reſembling thoſe of the Lapis Specularis, but of a glorious Yellow; very weighty, and ſometimes holding a ſmall Quantity of Gold.
There are, beſide this fine Orpiment, two other leſs beautiful Kinds; the one compoſed of an impurer Subſtance, reſembling common Sulphur, ſpangled all over with ſmall Flakes of the fine foliaceous Kind; the other more impure than the laſt, and tinged of a paler or deeper Green in many Places, from Particles of Copper. Theſe are what may be called the three different Kinds of this Foſſil; but there are, beſide theſe, almoſt endleſs Varieties of it, in regard to its deeper or paler Colour, and the extraneous Matters contained in it.
Yellow Orpiment burns to a Redneſs in the Fire, emitting a nauſeous Smell; and this red Maſs is ſometimes called red Orpiment: But the genuine and natural red Orpiment is the Sandarach here mentioned; this the Arabians call Zarnich-Abmer; it is of the ſame Nature with the former, but generally in larger Maſſes, and not of that foliaceous Texture, but in more compact Glebes.
All the Kinds of Orpiment and Sandarach are found in the Mines of Gold, Silver, and Copper; and ſometimes two or more of them
there are many Kinds of each, ſeveral of which will be ſpoken of hereafter: They are all of a fine argillaceous Texture, moſt of them eaſily crumbling to pieces, and ſtaining the Fingers in handling. They are uſed in Medicine and by the Painters. The common yellow Ochre is a cheap and very uſeful Colour: And the common Reddle is often ſold in the Druggiſts Shops either in its native State, if pale enough, as it ſometimes is; or mixed with Whiting, under the Name of Bole Armeniac.
The Ochres all contain more or leſs Iron; for the yellow ones become red by burning.
