Metamorphic Or Sedimentary (With Staining)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Gravel variety)

Silicon Dioxide (SiO2)

Granite Gneiss

Gneiss (derived from granitic protolith)

Metamorphic, Mineral (within a rock type)

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

sedimentary

Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)

Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.

Graphite

Graphite (C)

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily Quartz / Chalcedony: SiO2)

Petrified Wood

Silicified wood (Quartz, SiO2)

Mineral (specifically, a variety of the mineral species Pyrope-Almandine Garnet)

Garnet (Red Garnet)

Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).

Greenschist

Greenschist facies rock

Metamorphic

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (likely tumbled or naturally water-worn)

Quartz (SiO₂ - Silicon Dioxide)

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Pyrite

Pyrite (FeS2)

Quartz Crystal

Quartz (SiO₂)

Banded Onyx (Green Onyx)

Banded Calcite or Travertine (CaCO3)

Sedimentary

Banded Gneiss (River Cobble)

Gneiss (a high-grade metamorphic rock)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Pyrite

Iron Sulfide (FeS2)

Limonite Pseudomorph after Pyrite

Goethite/Limonite FeO(OH)·nH2O replacing Pyrite FeS2

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Mineral; variety of Quartz

Green Aventurine

Aventurine (Silicon dioxide, SiO₂)

Petrified Wood

Silicified Wood (SiO2)

Quartz

Quartz (SiO2, Silicon Dioxide)

Anthracite Coal

Anthracite (a form of coal, primarily carbon)

sedimentary

White Marble

Recrystallized Calcite (CaCO3)

metamorphic or sedimentary

River Pebble (likely Quartzite or Chert)

Silicon Dioxide (SiO2)

Jasper with Epidote

Silicon Dioxide (SiO2) with Calcium Aluminum Iron Sorosilicate [Ca2Al2Fe3+Si3O12(OH)]

sedimentary/metamorphic

Quartz

Quartz (SiO₂)

Quartz

Quartz (Silicon Dioxide, SiO2)

Red Jasper (Banded Jasper)

Silicon Dioxide (SiO2) with Hematite impurities

sedimentary

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

metamorphic and sedimentary

Slate with Red Sandstone Landscaping Rock

Foliated Pelitic Metamorphic Rock (Slate) and Ferruginous Sandstone

Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)

Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)

Metamorphic

Veined Quartz

SiO2 (Silicon Dioxide)

Garnet (likely Almandine or a blend)

Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.

Quartz

Quartz (SiO2 - Silicon Dioxide)