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Carbonates |
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magnesite |
MgCO3 |
1) veins or masses after
mafic minerals, 2) Mg-rich schist, 3) rare as a primary mineral in chemical
sediments, 4) replaces calcite or dolomite in limestone |
olivine, pyroxene,
serpentine, and brucite in ultramafic rocks; calcite and dolomite in
sedimentary rocks |
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rhodochrosite |
MnCO3 |
1) Mn-rich metamorphic
rocks, 2) primary mineral in sulfide veins, 3) secondary mineral in residual
deposits |
other Mn-rich minerals,
sulfide minerals, clay minerals and Fe oxides and hydroxides |
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Sorosilicates |
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CLINOZOISITE-EPIDOTE |
Ca2(Al,Fe3+)3Si3O12(OH) |
1) low- to
medium-grade metabasites and marble, 2) rare in igneous rocks, 3)
retrogressed Fe-rich minerals |
actinolite,
chlorite, albite, diopside, grossular, vesuvianite, carbonate, quartz,
plagioclase, garnet, biotite; epidote and clinozoisite are commonly
associated with zoisite |
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Zoisite is
an orthorhombic aluminous epidote with similar occurrence; allanite is a
rare-earth-element (REE) epidote. |
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Phyllosilicates |
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(serpentine) |
Mg phyllosilicates |
1)
secondary mineral in mafic and ultramafic igneous rocks 2) marbles |
magnesium
silicates, carbonates, hydroxides, and oxides, olivine, pyroxene, amphibole,
magnesite, spinel, chromite, magnetite, brucite, talc |
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Serpentine
is a group consisting of chrysotile (3 polymorphs), antigorite, and
lizardite. All belong to the kaolinite-serpentine group of phyllosilicates. |
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talc |
Mg phyllosilicate |
1)
hydrothermally altered mafic and ultramafic rocks, 2) metamorphism of siliceous dolomite |
serpentine,
magnesite, olivine, calcite, dolomite, tremolite, magnetite, chlorite,
anthophyllite |
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(chlorite) |
Mg, Al, Fe phyllosilicate |
1) low to
intermediate-grade metamorphic rocks 2) secondary mineral after biotite,
muscovite, and other mafic silicates |
quartz,
feldspars, epidote, muscovite, actinolite, albite, and a number of
ferromagnesian silicates |
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Chlorite
is a group of 10 minerals with the general formula A4-6Z4O10(OH,O)8 |
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