Litharge
| Litharge | ||
|---|---|---|
Mohs scale hardness 2 | | |
| Luster | greasy, dull | |
| Diaphaneity | transparent | |
| References | [2][3][4] | |
Litharge (from Greek lithargyros, lithos 'stone' + argyros 'silver' λιθάργυρος) is one of the natural mineral forms of
lead oxides in air.[5] This is often done with a set of bellows pumping air over molten lead and causing the oxidized product to slip or fall off the top into a receptacle, where it quickly solidifies in minute scales.[6]
- PbO2 –(293 °C)→ Pb12O19 –(351 °C)→ Pb12O17 –(375 °C)→ Pb3O4 –(605 °C)→ PbO
Historical terminology
Historically, the term litharge has been combined to refer to other similar substances. For example, litharge of
red lead, giving it a red color; litharge of bismuth is a similar result of the oxidation of bismuth; and litharge of silver is litharge that comes as a by-product of separating silver from lead. In fact, litharge originally meant the mineral residue from silver refining. The term has also been used as a synonym for white lead or red lead.[7]
Litharge smelting
According to Probert, "silver ore, litharge (crude lead oxide) flux and charcoal were mixed and smelted in very small clay and stone furnaces. Resulting silver-bearing lead bullion was later refined in a second furnace which yielded fine silver, and litharge skimmings which were used again."[8]
References
- S2CID 235729616.
- ^ Mineralienatlas
- ^ Mindat
- ^ Webmineral data
- ^ N.N. Greenwood, A. Earnshaw, "Chemistry of Elements", 2nd edition, Butterworth-Heinemann, 1997.
- ^ "VI. Semivitrified Oxide of Lead - Oxide of Lead. - Plumbi Oxidum. Us. - Litiiargyrum. Br. - Litharge".
- ^ "litharge". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
- ISBN 0860785130.
Further reading
- Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Litharge". Handbook of Mineralogy. Mineral Data Publishing. Retrieved 14 March 2022.
- Klein, Cornelis; Hurlbut, Cornelius S. Jr. (1993). Manual of mineralogy: (after James D. Dana) (21st ed.). New York: Wiley. ISBN 047157452X.