Sedimentary (Secondary Classification For A Weathered Mineral Specimen)

Sandstone or Mudstone with Iron Staining

Ferruginous Sandstone/Mudstone

Banded Chert or Chert with Quartz Veins

Chert (SiO2)

Chert (specifically Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

River Pebble (Gneiss or Quartzite variant)

Course-grained Metamorphic Rock (likely SiO2 dominant)

Epidote Water-Worn Pebble

Epidote {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Ferruginous Chert (Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Quartzite Cobble

Quartzite (primarily SiO2)

Ironstone Concretion (Moqui Marble)

Iron Oxide Concretion (Goethite and Hematite around a Sandstone core)

Chert (Flint/Chalcedony)

Microcrystalline Quartz (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Pebble

Clast (specifically a granule or small pebble)

Blue Calcite

Calcium Carbonate (CaCO3)

Sandstone (with potential iron-oxide staining)

Arenite (primarily SiO2)

Diabase (Greenstone)

Diabase or Dolerite

Ironstone with Pyrite

Ferruginous Sandstone (Fe2O3) with minor Sulfide minerals (FeS2)

Sandstone

Arenite (primarily SiO2, silica)

Yellow Chert (Jasper)

Microcrystalline Quartz (SiO2)

Jasper Beach Pebble

Silicon Dioxide (SiO2) - Macro-crystalline Quartz

Sandstone (Ferruginous)

Arenite (complex silicate composition with iron oxides)

Basalt with inclusion

Basalt (Aphanitic-Porphyritic texture)

Biotite Mica

K(Mg, Fe)3AlSi3O10(F, OH)2

Orange Calcite

Calcium Carbonate (CaCO3)

Sandstone (River Cobble)

Clastic sedimentary rock (primarily SiO2 with various lithic fragments)

Copper Ore (with Azurite and Malachite)

Cuprite, Azurite (Cu3(CO3)2(OH)2), Malachite (Cu2(CO3)(OH)2)

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Basalt Pebble

Basalt (Aphanitic Mafic Igneous Rock)

Bauxite

Al2O3·2H2O (principally composed of gibbsite, boehmite, and diaspore)

Quartz (Smoky/Milky variety)

Silicon Dioxide (SiO2)

Jasper with Quartz inclusions

Silicon Dioxide (SiO2) - Microcrystalline Chalcedony

Quartz (Druzy or Geode fragment)

Silicon Dioxide (SiO2)

Gold Nugget

Native Gold (Au)

Hematite

Iron(III) oxide (Fe2O3)

Sandstone (clastic)

Clastic Sedimentary Rock (primarily composed of SiO2)

Sandstone (Ferruginous)

Arenite (SiO2 with iron oxide impurities)

Basalt with Quartz Veining

Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins

Ironstone Concretion (Moqui Marble type)

Iron oxide concretion (Goethite/Hematite and Sandstone)

Geode (Quartz)

Silicon Dioxide (SiO2)

Jasper (Iron-stained Chalcedony)

SiO2 with Fe2O3 (Iron Oxide) impurities

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Sandstone (Water-worn)

Arenite

Iron Ore / Ironstone Concretion

Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)