Native SAL Ammoniac. This salt, according to Mongou, is met with in the form of an efflorescence on the surface of the earth, or adhering in powder to rocks. Sometimes, as in Persia and the country of the Kalmucks, it is found as hard as stone. It is met with of different colours, as grey, black, green, and red, in the neighbourhood of volcanoes, in the caverns or grottoes of Puzzuoli, and in the mineral lakes of Tuscany, as well as in some mountains of Tartary and Thibet. At Sol-fatera, near Naples, it is found in the crevices, of a yellowish colour, like common sal-ammoniac more than once sublimed. For common sal-ammoniac, see CHEMISTRY-Index at Ammoniac and Ammoniacal Salt.