Sedimentary (Secondary Classification For A Weathered Mineral Specimen)

Chalcedony Nodule (Agate/Chert)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Native Copper

Native Copper (Cu)

Yellow Ocher (Limonite)

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

Limonite (Iron Ore)

FeO(OH)·nH2O

Basalt with Caliche Crust

Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating

Fossilized Gastropod in Chert/Limestone

Internal mold of Gastropoda (Class) with CaCO3 or SiO2 mineral formula

Sandstone (Weathered Coastal Boulder)

Arenite (composed primarily of SiO2)

Sandstone (Greywacke)

Arenite / Greywacke Sandstone

Sandstone (Weathered Cobble)

Clastic sedimentary rock (primarily SiO2)

Agate (or Chalcedony)

Silicon Dioxide (SiO2)

Turquoise and Hematite

Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Hematite (Fe2O3)

Satin Spar (Gypsum)

Hydrous Calcium Sulfate (CaSO4·2H2O)

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Chert (with Limestone/Carbonate matrix)

Sedimentary cryptocrystalline silica (SiO2)

Chert (with possible fossils)

Microcrystalline quartz (SiO2)

Quartz

Silicon dioxide (SiO2)

Turquoise

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

Limonite (Ironstone) Concretion

FeO(OH)·nH2O (Hydrous ferric oxide)

Malachite

Copper(II) carbonate hydroxide [Cu2CO3(OH)2]

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Vein in Host Rock (clastic sediment)

Silicon Dioxide (SiO2) in matrix

Agate

Silicon dioxide (SiO2) - variety of chalcedony

Carnelian (a variety of Chalcedony)

SiO2 (Silicon Dioxide) primarily colored by iron oxide (Hematite)

Limonite (Iron Ore)

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Sulfur on Quartz

Native Sulfur (S8) with Quartz (SiO2)

Chalcedony (Quartz Nodule)

Silicon Dioxide (SiO2)

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO₂)

Sandstone

Arenite (SiO2 secondary)

Ironstone Concretion

Ferruginous Sandstone / Siderite Concretion

Turquoise

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

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Weathered Sandstone with Algae Growth

Arenite

Corundum (Sapphire)

Corundum (Al2O3)

Blue Sapphire

Corundum (Al2O3 with iron and titanium trace elements)

Limonite (Yellow Ochre)

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Snakeskin Agate

Agate (Cryptocrystalline Quartz, SiO2)

Turquoise in Matrix

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

River Cobble (Quartzite-rich Sandstone)

Clastic Sedimentary Rock (Litharenite/Quartzite transition)

Blue Calcite

Calcium Carbonate (CaCO3)

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

Yellow Jasper / Chalcedony

Silicon Dioxide (SiO2) with iron inclusions