| Reference Type | Journal (article/letter/editorial) |
|---|
| Title | Manganoan fayalite and products of its alteration from the Strzegom pegmatites, Poland |
|---|
| Journal | Mineralogical Magazine | ISSN | 0026-461X |
|---|
| Authors | Janeczek, J. | Author |
|---|
| Year | 1989 (June) | Volume | 53 |
|---|
| Issue | 371 |
|---|
| Publisher | Mineralogical Society |
|---|
| Download URL | https://rruff.info/doclib/MinMag/Volume_53/53-371-315.pdf+ |
|---|
| DOI | doi:10.1180/minmag.1989.053.371.07Search in ResearchGate |
|---|
| Generate Citation Formats |
|---|
| Mindat Ref. ID | 1509 | Long-form Identifier | mindat:1:5:1509:1 |
|---|
|
| GUID | 0 |
|---|
| Full Reference | Janeczek, J. (1989) Manganoan fayalite and products of its alteration from the Strzegom pegmatites, Poland. Mineralogical Magazine, 53 (371) 315-325 doi:10.1180/minmag.1989.053.371.07 |
|---|
| Plain Text | Janeczek, J. (1989) Manganoan fayalite and products of its alteration from the Strzegom pegmatites, Poland. Mineralogical Magazine, 53 (371) 315-325 doi:10.1180/minmag.1989.053.371.07 |
|---|
| In | (1989, June) Mineralogical Magazine Vol. 53 (371) Mineralogical Society |
|---|
| Abstract/Notes | AbstractNodules of manganoan fayalite occur in schlieren pegmatities in the vicinity of Strzegom, Lower Silesia. The fayalite, Na0.02(Fe1.812+Mn0.16Mg 0.03)Si0.99O4, is unzoned and non pleochroic. 2Va = 42° a 4.826(3), b 10.500(2), c 6.102(2) A, d130obs. = 2.83 Å, d130calc. = 2.833 Å, D = 4.35 g cm-3, Dcalc. = 4.353 g cm-3. The role of Na+ ions in the fayalite chemistry is discussed. The fayalite underwent multi-stage hydrothermal alteration beginning at the highest temperature (440°C) of homogenization of gaseous-fluid inclusions in quartz adjacent to the fayalite grains. Increase in fO2 and then in PH2O resulted in the formation of magnetite-quartz and Mn-grunerite-magnetite-quartz aggregates within the fayalite grains. The fayalite is mantled by a Mn-greenalite-magnetite rim, Mn-grunerite-magnetite-Mn-minnesotaite zone in a stilpnomelane or greenalite-rich groundmass. The minnesotaite is believed to have formed at the expense of grunerite. Stilpnomelane, the most abundant silicate phase in the rim, is the product of biotite and presumably greenalite alteration at the second stage of increasing Na activity (the crystallization of cleavelandite) in the pegmatites. The fayalite is also heavily altered to iddingsite—a composite mixture of amorphous FeOOH and silica. The iron-hydroxide recrystallized partially to poorly-crystalline goethite. |
|---|
These are possibly similar items as determined by title/reference text matching only.
