Sedimentary (Jasper), Mineral (Aquamarine)

Limonite Concretion

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

Limonite (Iron Ore)

Goethite and related iron hydroxides (FeO(OH)·nH2O)

Sandstone (Calcareous or Ferruginous)

Clastic sedimentary rock (SiO2 with CaCO3 or Fe2O3 cement)

Limonite Concretion (Ironstone)

Limonite (Hydrated Iron(III) Oxide-Hydroxide, FeO(OH)·nH2O)

Pyrite in Matrix (Fool's Gold)

Iron Sulfide (FeS2)

Sandstone (Quartzose)

Arenite (Siliciclastic sedimentary rock)

Concrete with Aggregate

Artificial Conglomerate (Cement and Aggregate)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)

Banded Onyx (Mexican Onyx / Travertine)

Calcite (CaCO3) - Banded Travertine

Sandstone

Arenite (Siliclastic Sedimentary Rock)

Sandstone

Sandstone (Sedimentary rock composed of silicate grains)

Sandstone with Concretions / Liesegang Rings

Arenite with iron oxide banding

Limonite/Goethite on Shale

Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock

Specular Hematite

Hematite (Fe2O3)

Pyrite on Quartz matrix

Iron Disulfide (FeS2) on Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Rhodochrosite

Manganese Carbonate (MnCO3)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Sandstone (Ferruginous)

Arenite with Iron Oxide cement

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Garnet (specifically Almandine)

Almandine - Fe3Al2(SiO4)3

Pebble

Clast (specifically a granule or small pebble)

Sandstone Cobble

Clastic Sedimentary (Sandstone)

Sandstone or Limestone

Arenite or Calcareous Sedimentary Rock

Celadonite in Basalt (Green Earth)

Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)

Concretion (Sandstone)

Sandstone Concretion

Sandstone

Arenite (SiO2 dominant)

Boxwork Siderite or Sepatarian Nodule Weathering

Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment

Gneiss (Cobble)

Gneiss

Sedimentary Breccia

Breccia (Clastic Sedimentary Rock)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Green Quartz (Prasiolite/Adventurine/Jasper)

Silicon Dioxide (SiO2)

Sandstone (Weathered Cobble)

Clastic sedimentary rock (primarily SiO2)

Geode (Unopened)

Siliceous Septarian Concretion / Geode (SiO2)

Septarian Nodule (Septarian Dragon Stone)

Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)

Banded Iron Formation (BIF) / Tiger Iron

Ferruginous Chert (primarily Quartz [SiO2] and Hematite/Magnetite [Fe2O3/Fe3O4])

Clear Quartz

Silicon Dioxide (SiO2)

Quartz on Schist

Silicon Dioxide (SiO2) on Foliated Metamorphic Rock

Sandstone (Quartzite Pebble)

Arenite (SiO2)

Shale

Fissile mudstone (rich in clay minerals and quartz)