Sedimentary Rock (Technically Chert, A Microcrystalline Quartz)

Sandstone with Iron Oxide (Limonite/Hematite)

Ferruginous Sandstone (SiO2 with FeO(OH)·nH2O)

Limestone with Weathering Rind

Calcium Carbonate (CaCO3) - Bioclastic or Micritic Limestone

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Jasper or Agate-bearing Chert

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Ferruginous Sandstone

Clastic sedimentary rock (primarily Quartz with Iron Oxide cement)

Herkimer Diamond in Matrix

Quartz (SiO2) in Dolostone (CaMg(CO3)2)

Black Limestone with Calcite Veining

Bituminous Limestone (CaCO3 with Organic Carbon inclusions)

Iron-stained Quartzite

Quartzite with Limonite/Hematite staining (SiO2 with FeO(OH)·nH2O)

Banded Agate (specifically Sardonyx)

Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz

Sandstone (Weathered Cobble)

Clastic Sedimentary Rock (primarily SiO2)

Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)

Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein

Carnelian

Carnelian Chalcedony (SiO2 with iron oxide impurities)

River Cobble (likely Quartzite or Chert)

Quartzite (SiO2)

Green Aventurine

Aventurine Quartz (SiO2 with inclusions)

Quartzite River Rock

Quartzite (SiO2)

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Sandstone (Quartz-rich)

Arenite (composed primarily of SiO2)

River Quartzite Siltstone

Quartz-rich Meta-siltstone (SiO2 dominated)

Sandstone with Foliose Lichen

Arenite (Rock matrix) with Xanthoparmelia or Flavoparmelia (Lichen genus)

Red Sandstone

Clastic Terrigenous Sedimentary Rock (typically Hematitic Quartz Arenite or Arkose)

Sandstone Concretion with Quartz Center

Sedimentary Clastic Rock (SiO2 matrix with Quartz core)

Orbicular Rhyolite (Rainforest Jasper)

Rhyolite containing Spherulites (SiO2 with impurities)

Sandstone

Arenite (SiO2 based with mineral cement)

Quartz Pebble

Silicon Dioxide (SiO2)

Picture Jasper

Silicified sedimentary or volcanic rock (primarily SiO2)

Stromatolite

Biogenic Sedimentary Rock (composed predominantly of CaCO3)

River Quartzite (or Quartz Cobble)

Quartzite (primarily Silicon Dioxide - SiO2)

Sandstone with Iron Concretion

Arenite with Limonite/Goethite Concretion

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Jasper (with Manganese or Iron inclusions)

Silicon Dioxide (SiO2)

Fancy Jasper (Mookaite style)

Silicon Dioxide (SiO2) with iron oxide impurities

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Quartzite Pebble

Quartzite (SiO2)

Chalcedony (Agate/Carnelian)

Cryptocrystalline Silicon Dioxide (SiO2)

Coal

Bituminous or Anthracite coal (carbon-rich sedimentary rock)

Carnelian (Orange Agate)

Silicon Dioxide (SiO2)

Ironstone Concretion

Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Banded Gneiss

Gneiss (Metamorphic Rock)

Ironstone (likely Limonite or Goethite)

Ferruginous sedimentary rock (FeO(OH)·nH2O)

Sandstone (Yellow/Tan Sandstone)

Arenite (primarily Quartz, SiO2)

Microcrystalline Limestone Pebble

Carbonate sedimentary rock (Calcium Carbonate, CaCO3)