Themes of the Day:

• Island Silicate (Orthosilicate) Minerals

Olivine

• Olivine Properties - see Nesse p. 306
• Olivine Structure
• Compositional Variation in Physical and Optical Properties
• Forsterite - Fayalite Phase Diagram
• Olivine in Thin Section - a more colorful view, and another
• Olivine Thin Section GigaPan
• Associated Minerals:
  • Spinel, Garnet, other High Pressure minerals in Mantle rocks
  • Chromite, Pyroxenes (see below), Anorthite (Friday) in Ultramafic and Mafic rocks
  • Serpentine, and Talc as alteration minerals
  • Olivine also occurs as a metamorphic mineral in calc-silicate rocks (discussed later).

Garnet Group

• Garnet Properties - see Nesse p. 310
• Garnet Structure
• Garnet Compositional Variation - X₃Y₂(SiO₄)₃ - Table 16.2
  • Pyralspite Series: Y = Al³⁺
  • Pyrope - Mg₃Al₂(SiO₄)₃
  • Almandine - Fe₃Al₂(SiO₄)₃
  • Spessartine - Mn₃Al₂(SiO₄)₃
  • Ugrandite Series
  • Uvarovite - Ca₃Cr₂(SiO₄)₃
  • Grossular - Ca₃Al₂(SiO₄)₃
  • Hydrogrossular - Ca₃Al₂(SiO₄)_3-x(OH)_4x
  • Andradite - Ca₃Fe³⁺₂(SiO₄)₃
• Garnet in Hand Sample and Thin Section - another thin section
• Associated Minerals:
  • Pyrope: Olivine, Pyroxene, other High Pressure minerals in Mantle rocks
  • Almandine: Biotite, Muscovite, Staurolite, Aluminosilicates, etc. in metamorphosed pelitic rocks (meta-mudstones)
  • Grossular: Calcite, Diopside, Wollastonite, Epidote, etc. in Skarns and metamorphosed calc-silicate rocks
  • Spessartine: in some aplites and pegmatites (igneous)

The Aluminosilicates

• Aluminosilicate Structures - see Nesse p. 314
• Aluminosilicate P-T Phase Diagram
• Aluminosilicates in Thin Section
• Andalusite Properties - see Nesse p. 316 - in thin section
• Sillimanite Properties - see Nesse p. 318
• Kyanite Properties - see Nesse p. 319 - in thin section
• Associated Minerals:
  • Biotite, Muscovite, Staurolite, Almandine Garnet, etc. in metamorphosed pelitic rocks (meta-mudstones)

Other Island Silicates

• Zircon Properties - see Nesse p. 312 - Zircon in Thin Section
• Staurolite Properties - see Nesse p. 319 - Staurolite in Thin Section - another thin section
• Chloritoid Properties - see Nesse p. 321 - Chloritoid Structure - Chloritoid in Thin Section - another thin section
• Titanite (Sphene) Properties - see Nesse p. 322 - Titanite in Thin Section - another thin section