Sedimentary Rock (Possibly A Conglomerate Or Coarse Grained Sandstone)

Shale or Siltstone

Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Slate

Slate (Metamorphic Rock)

Quartzite River Rock

Quartzite (primarily SiO2)

Granitoid (Granite/Diorite)

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica/Amphiboles)

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Quartz

Silicon dioxide (SiO2)

Quartzite (Iron-stained)

Quartzite (SiO2 with Fe-oxides)

Quartzite (River Pebble)

Metamorphic Quartzite (SiO2)

Granite Cobble

Phaneritic Plutonic Felsic Rock

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (Hematite/Goethite shell with Sandstone core)

Sandstone (Picture Sandstone)

Arenite (primarily SiO2 with iron oxide impurities)

Quartzite with Iron Staining

Silicon Dioxide (SiO2) with Fe2O3 impurities

Quartzite

Quartzite (SiO2)

Quartzite with Garnet

Garnetiferous Quartzite (SiO2 + X3Y2(SiO4)3)

Quartzite Pebble

Quartzite (SiO2)

Gneiss

Gneiss (Metamorphic high-grade)

Quartzite

Quartzite (primarily SiO2)

Marble

Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).

Gneiss

Gneiss (High-grade metamorphic rock)

Quartz Vein in River Siltstone

Crystalline Quartz (SiO2) in Siliclastic Matrix

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Red Quartzite / Ferruginous Sandstone

Quartzite (SiO2 with iron oxide impurities)

Pyrite (on Shale/Matrix)

Iron Disulfide (FeS2)

Banded Gneiss

Gneiss (pronounced "nice")

Banded Slate (Lithified Mudstone)

Low-grade Metamorphosed Mudstone / Slate

Quartzite River Rock

Quartzite (primarily SiO2)

Limonite Concretion

Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O

Ironstone Concretion (Iron-rich Mudstone)

Siderite / Geothite concretion (FeCO3 / FeO(OH))

Quartzite River Pebble

Quartzite (primarily Silicon Dioxide, SiO2)

Quartzite

Quartzite (SiO2)

Black Opal

Hydrated Silica (SiO2·nH2O)

Granite

Granite (Felsic intrusive igneous rock)

Quartzite

Quartzite (primarily Silicon Dioxide, SiO2)

Quartzite (Iron-stained)

Quartzite (mostly SiO2 with Fe2O3 impurities)

Quartzite

Quartzite (primarily SiO2)

Sandstone (Banded)

Clastic sedimentary rock (primarily SiO2)

Quartz-veined Mudstone or Argillite

SiO2 (Quartz) in Siltstone/Mudstone matrix

Sandstone (Banded)

Clastic Sedimentary Rock (primarily SiO2)

Quartzite (Quartz-rich Cobble)

Quartzite (SiO2)

Quartzite with Feldspar

Quartzite (mainly SiO2) with inclusions of Potassium Feldspar (KAlSi3O8)

Red Quartzite

Quartzite (primarily SiO2)