Minnesotaite
| Minnesotaite | ||
|---|---|---|
2V angle Measured: 4° | | |
| Dispersion | r < v moderate | |
| References | [2][3][4] | |
Minnesotaite is an iron silicate mineral with formula: (Fe2+,Mg)3Si4O10(OH)2. It crystallizes in the triclinic crystal system and occurs as fine needles and platelets with other silicates.[2] It is isostructural with the pyrophyllite-talc mineral group.[3]
Occurrence
Minnesotaite was first described in 1944 for occurrences in the banded iron formations of northern Minnesota for which it was named. Co-type localities are in the Cuyuna North Range, Crow Wing County and the Mesabi Range in St. Louis County.[3][5]
It occurs associated with quartz, siderite, stilpnomelane, greenalite and magnetite.[2][6] In addition to the low grade metamorphic banded iron formations it has also been reported as an alteration mineral associated with sulfide bearing veins.[3]
References
- S2CID 235729616.
- ^ a b c Handbook of Mineralogy
- ^ a b c d Minnesotaite on Mindat.org
- ^ Minnesotaite on Webmineral
- ^ Gruner, John (1946). The Mineralogy and Geology of the Taconites and Iron Ores of the Mesabi Range, Minnesota. Office of the Commissioner of the Iron Range Resources and Rehabilitation. p. 8,38.
- ^ Gruner, John W., The Composition and Structure of Minnesotaite, a Common Iron Silicate in Iron Formations, American Mineralogist, 1944, 29, 363-372
