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Geosciences LibreTexts

2: Minerals (Exercises)

  • Page ID
    2041
  • [ "article:topic" ]

    Q2.1 Cations, anions and ionic bonding

    Lithium (3) 2 in shell one and 1 in shell two It loses an electron and becomes a +1 cation
    Magnesium (12) 2 in shell one, 8 in shell two and 2 in shell three It loses two electrons and becomes a +2 cation
    Argon (18) 2 in shell one, 8 in shell two and 8 in shell three It is electronically stable, and does not become an ion
    Chlorine (17) 2 in shell one, 8 in shell two and 7 in shell three It gains an electron and becomes a -1 anion
    Beryllium (4) 2 in shell one and 2 in shell two It loses two electrons and becomes a +2 cation
    Oxygen (8) 2 in shell one and 6 in shell two It gains two electrons and becomes a -2 anion
    Sodium (11) 2 in shell one, 8 in shell two and 1 in shell three It loses an electron and becomes a +1 cation

     

    Q2.2 Mineral groups

    Name Formula Group
    sphalerite ZnS sulfide
    magnetite Fe3O4 oxide
    pyroxene MgSiO3 silicate
    anglesite PbSO4 sulfate
    sylvite KCl halide
    silver Ag native
    fluorite CaF2 halide
    ilmenite FeTiO3 oxide
    siderite FeCO3 carbonate
    feldspar KAlSi3O8 silicate
    sulphur S native
    xenotime YPO4 phosphate

    Q2.3 Make a tetrahedron 

    Responses will vary

    Q2.4 Oxygen deprivation

    Single chain silicate: 1:3 (silicon to oxygen), double chain silicate: 7:19 (or 1:2.71)

    Q2.5 Ferromagnesian silicates

    Mineral Formula Ferromagnesian Silicate?
    olivine (Mg,Fe)2SiO4 yes
    pyrite FeS2 no (it’s a sulphide, not a silicate)
    plagioclase CaAl2Si2O8 no
    pyroxene MgSiO3 yes
    hematite Fe2O3 no (it’s an oxide, not a silicate)
    orthoclase KAlSi3O8 no
    quartz SiO2 no
    amphibole Fe7Si8O22(OH)2 yes
    muscovite K2Al4 Si6Al2O20(OH)4 no
    magnetite Fe3O4 no (it’s an oxide, not a silicate)
    biotite K2Fe4Al2Si6Al4O20(OH)4 yes
    dolomite (Ca,Mg)CO3 no (it’s a carbonate, not a silicate)
    garnet Fe2Al2Si3O12 yes
    serpentine Mg3Si2O5(OH)4 yes