Siltstone Concretion
Carbonate-cemented Siltstone Concretion
sedimentary
Category
Mineral, Sediment
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Sandstone (Gneissic or Banded)
Clastic Sedimentary Rock (composed predominantly of SiO2)
sedimentary
Tumbled milky quartz
Quartz, SiO₂
mineral
Sandstone (Iron-stained)
Arenite with Limonite/Hematite staining
sedimentary
Fossil-bearing Sedimentary Rock
Sedimentum cum fossili
fossil
Banded Chert
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Quartz River Pebble (Quartzite)
Metamorphic Quartzite (SiO2)
metamorphic
Vivianite
Vivianite, Fe2+3(PO4)2·8H2O
mineral
Ironstone Concretion (Nutstone)
Ironstone (with High Limonite/Hematite Content)
sedimentary
Fossilized Shark Tooth
Carcharocles sp. or similar (Fossilized Fluorapatite)
sedimentary
Rounded quartz-rich beach pebble
Likely milky quartz or quartzite (SiO₂)
mineral
Sandstone with Quartz Vein
Arenite with Crystalline Silica (SiO2)
sedimentary
Green Aventurine
Quartz with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
mineral
Turritella Gastropod Fossil
Turritella (mollusk fossil in sedimentary matrix)
fossil
Red Jasper
Silicon Dioxide (SiO2) with iron inclusions
mineral
Sandstone (Water-worn)
Arenite
sedimentary
Bivalve Fossil (Clam Stone)
Phylum Mollusca, Class Bivalvia
fossil
Bivalve Internal Mold Fossil
Steinkern (Bivalvia mold)
fossil
Rounded gray river cobble, likely basaltic-andesite or andesite
Fine-grained intermediate to mafic volcanic rock; commonly plagioclase ± pyroxene, with possible alteration minerals
igneous
Heart-shaped Quartz
Silicon Dioxide (SiO2)
mineral
Jasper (specifically Owyhee or Picture Jasper variety)
Jasper (Silicon Dioxide, SiO2)
sedimentary
River Pebble (Gravel Pebble)
Stream-rounded Rock / Siliciclastic Pebble
sedimentary
Milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Shark Tooth Fossil
Chondrichthyes (class) fossilized tooth
fossil
Sandstone (Graywacke)
Clastic Sedimentary Rock (Lithic Sandstone)
sedimentary
Shale
Laminated Mudstone
sedimentary
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Fossilized Shark Tooth
Bioapatite (Calcium Hydroxyapatite) replacement
mineral
Shark Tooth Fossil
Vertebrate fossilized tooth
fossil
Fossilized oyster shell in limestone
Bivalvia fossil; chiefly calcite (CaCO₃)
fossil
Bumblebee Jasper (technically Bumblebee Stone)
Calcite, Aragonite, and Realgar/Orpiment mixture (SiO2 + CaCO3 + As2S3/As2S2)
sedimentary (volcanic)
Leopard Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Iron Concretion
Ferruginous concretion (Fe2O3·nH2O / FeO(OH))
sedimentary
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
River Rock
Polished Siliceous Rock / Quartzite Pebble
sedimentary
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Ironstone Concretion
Ferruginous Siltstone/Ironstone (Fe2O3)
sedimentary
Sandstone Concretion
Ferruginous Sandstone Concretion
sedimentary
Sandstone (likely Greywacke variant)
Arenite
sedimentary
Sandstone Concretion
Sedimentary Clastic Rock (Silicate-rich)
sedimentary
Glauconite
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary