Metamorphic Or Igneous (Context Dependent)

Quartzite Pebble (Beach Stone)

Quartzite (primarily SiO2)

Quartzite (River Cobble)

Quartzite (Metamorphosed Quartz Sandstone, SiO2)

Quartzite (Ferruginous)

Recrystallized Quartz (SiO2) with Iron Oxide inclusions

Quartzite (or Milky Quartz pebble)

Quartzite (Metamorphosed Sandstone) / Silicon Dioxide (SiO2)

Blue Quartzite (Aventurine)

Silicon Dioxide (SiO2) with mineral inclusions

Unakite

Epidotized Granite

Mica Schist

Mica Schist (Complex Silicate Rock)

Schist (Diamond Drill Core)

Mica Schist

Pink Quartzite

Quartzite (SiO2 with iron oxide impurities)

Quartzite

Quartzite (primarily SiO2)

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2

Quartzite

Quartzite (SiO2)

Orange Quartzite / Carnelian Agate

Silicon Dioxide (SiO2)

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 - Muscovite component)

Quartz vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Lithic Matrix

Garnet Schist or Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Quartzite

SiO2 (Silicon Dioxide)

Mica Schist

Mica Schist (predominantly Muscovite or Biotite sheet silicates)

Marble

Metamorphosed Limestone (calcite formulation CaCO3)

Green Quartzite (River Stone)

Metamorphic Quartz (SiO2) with inclusions (typically Fuchsite or Chlorite)

Green Quartzite

Metamorphic Quartz (SiO2) with Chromium-rich inclusions (Fuchsite)

Slate

Foliated Metamorphic Rock (primarily clay minerals and micas)

River Pebble (Gneiss or Quartzite variant)

Course-grained Metamorphic Rock (likely SiO2 dominant)

Anthracite Coal

Anthracite (Carbon-based sedimentary-derived metamorphic rock)

Slate with Pyrite Inclusions

Foliated Metamorphic Rock (with Iron Sulfide FE-S2)

Slate with Quartz Vein

Foliated Metamorphic Rock (Mainly Quartz, Muscovite, Chlorite)

Blue Sapphire (faceted in jewelry)

Corundum (Al2O3)

Magnetite / Iron Ore

Magnetite (Fe3O4)

Schist

Mica Schist (primarily Muscovite and Quartz)

Quartzite Pebble (Beach Pebble)

Quartzite (primarily SiO2)

Sandstone (with potentially metamorphic or basaltic bands)

Arenite / Lithic Wacke

Labradorite

Labradorite (a calcium-enriched sodic plagioclase feldspar mineral - (Ca, Na)(Al, Si)4O8)

Orange Quartzite (Tumble-polished)

Quartzite (primarily SiO2)

Granite (Orthoclase rich)

Granite (composed primarily of Quartz and Potassium Feldspar KAlSi3O8)

Green Aventurine

Quartzite with Fuchsite (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

Yellow Quartzite (or Quartz River Pebble)

Silicon Dioxide (SiO2)

Yellow Quartzite (Orange Quartzite)

Silicon Dioxide (SiO2) with iron oxide staining

Yellow Quartzite River Cobble

Meta-quartzite (SiO2 with iron oxide staining)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Green Kyanite

Kyanite (Al2SiO5)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Anthracite Coal

Anthracite (Carbon-based organic sedimentary/metamorphic rock)