Global InformationMarshite information
| Marshite | |
|---|---|
 Exceptionally well crystallized specimen of the rare copper iodide marshite from the Rubtsovskoe Deposit, Altaiskii Krai, Western Siberia, Russian Federation. | |
| General | |
| Category | Halide mineral |
| Formula (repeating unit) | CuI |
| IMA symbol | Msh[1] |
| Strunz classification | 3.AA.05 |
| Dana classification | 9.1.7.3 |
| Crystal system | Isometric |
| Crystal class | Hextetrahedral (43m) |
| Space group | F43m |
| Unit cell | a = 6.05 Å (untwinned a = 6.6063(1) Å); Z=4 |
| Identification | |
| Color | Honey-yellow, exposed to air pink-red to brick-red |
| Crystal habit | Tetrahedral crystals, cubo-octahedral, crusts |
| Twinning | On {111} |
| Cleavage | {011} perfect |
| Fracture | Conchoidal |
| Tenacity | Brittle |
| Mohs scale hardness | 2.5 |
| Luster | Adamantine, greasy |
| Streak | Yellow |
| Diaphaneity | Transparent |
| Specific gravity | 5.68 |
| Density | 5.68 g/cm3 (measured), 5.71 g/cm3 (calculated) |
| Optical properties | Isotropic |
| Ultraviolet fluorescence | Dark red (SW, LW) |
| References | [2][3][4][5] |
Marshite (CuI) is a naturally occurring isometric halide mineral with occasional silver (Ag) substitution for copper (Cu).[6][7] Solid solution between the silver end-member miersite and the copper end-member marshite has been found in these minerals from deposits in Broken Hill, Australia.[8] The mineral's name is derived from the person who first described it, an Australian mineral collector named Charles W. Marsh.[2][3][4] Marsh drew attention to native copper iodide (Marshite) in the 1800s emphasizing its natural occurrence, it is not to be confused with copper (I) iodide a substance commonly synthesized in laboratory settings.[9][10]
One of marshite's distinguishing features is that prior to exposure to air the mineral is a faint honey-yellow color, once exposed to the air however it becomes a brick-red color.[2][3] Another characteristic useful in identifying marshite is the dark red color it fluoresces under short-wave (SW) and long-wave (LW) ultraviolet light.[2][4]
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ a b c d Handbook of Mineralogy - Marshite
- ^ a b c Mindat.org - Marshite
- ^ a b c Webmineral - Marshite
- ^ Cooper, M.A., and Hawthorne, F.C. (1997) “A note on the crystal structure of marshite”, The Canadian Mineralogist, 35: 785–786.
- ^ Prior, G.T. (1902) “The identity of kilbrickenite with geocronite: And analyses of miersite, marshite, and copper-pyrites”, Mineralogical Magazine, 13: 186–190.
- ^ Palache, C., Berman, H., Frondel, C. (1951) "The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc." John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged: pp. 20-22.
- ^ Millsteed, P.W. (1998) “Marshite - miersite solid solution and iodargyrite from Broken Hill, New South Wales, Australia“. Mineralogical Magazine, 62(4): 471–475.
- ^ Marsh, C.W. (1892) Proceedings of the Royal Society of New South Wales, 26: 326–332 (as Native copper iodide).
- ^ Marsh, C.W. and Liversidge, A. (1892) "On Native Copper Iodide (Marshite) and other Minerals from Broken Hill, N.S. Wales", Journal and Proceedings of the Royal Society of New South Wales, 26: 326–332.