Mineralogical chemistry

1871 Journal of the Chemical Society (Resumed)  
Eosite.--Ti~~ author describes a specimen of "vanadio-molybdate of lead " from Leadhills, which differs so strikingly in its crystallographic and chemical characters from its nearest allies, wulfenite and descloizite, that he regards it as a type of a new species, and on account of its aurora-red colour, gives it the above name. Its matrix, abundantly beset with crystals of cerussite, is cellular ochreous galena. The cerussite is in several points encrusted with moss-like aggregations of
more » ... regations of delicate, minute, acicular, yellow crystals of pyromorphite, which often completely cover in the small red octohedrons of eosite attached to the cerussite below. The measurements of the yellow crystals proved them to be regular hexagonal prisms, and an examination of the small amount of material a t disposal showed that it contained no vanadium. The crystals of eosite are below 4 millim. in size, and though readily detached from the cerussite, are onJy with difficulty freed from the pyromorphite; their hardness lies between 3 and 4, and, when crushed, they show slight traces of oleavage. The red of eosite is deeper than hhat of chromate of lead, and approaches that of realgar ; in powder it is brownish orange, somewhat darker than that of red chromate of lead. Eosite, when pulverized, becomes white in contact with hydrochloric acid, chloride of lead being formed. The yellow solution,
doi:10.1039/js8712400500 fatcat:k3m2o7hvfrdt3ovl26oifdqqci