Agate (Common Chalcedony)
Silicon Dioxide (SiO2)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Agate (Common Chalcedony)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (with Iron Oxide)
Gneiss (Pebble)
Gneiss
Sandstone
Sandstone (Sedimentary rock composed of silicate grains)
Banded Slate or Siltstone with Quartz/Calcite Veins
Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)
Caribbean Calcite
Calcium Carbonate with Argonite (CaCO3)
Sandstone (Quartzite-rich Cobble)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite
Chert (specifically Red Chert / Jasper nodule)
Silicon dioxide (SiO2)
Granite
Granite (Felsic Plutonic Rock)
Banded Agate (specifically Moss or River Agate variety)
Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite (SiO2 based with quartz grains)
Chert (and Chalcedony)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with FeO/Fe2O3)
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (composed mainly of SiO2)
Porphyritic Basalt (Chinese Flower Stone / Chrysanthemum Stone basalt variety)
Porphyritic Basalt containing Plagioclase Feldspar phenocrysts
Biotite (Black Mica)
Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2
Sandstone (Quartzose)
Arenite (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Basalt (Porphyritic)
Porphyritic Mafic Extrusive (Basalt)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Red Siltstone (or Red Shale)
Clastic Sedimentary Rock (Composition: primarily Quartz, Clay minerals, and Hematite Fe2O3)
Sandstone
Arenite
Basalt with Amygdules
Amygdaloidal Basalt
Pumice
Pumice (Vesicular Rhyolite/Andesite)
Sandstone
Arenite (primarily SiO2)
Basalt (with Plagioclase Phenocrysts)
Porphyritic Basalt
Basalt (with possible quartz veinsing)
Basalt
Shale
Shale (fine-grained clastic sedimentary rock)
Quartz (likely a clear or rock crystal variety)
Quartz (SiO2 - Silicon Dioxide)
Sandstone
Arenite (Clastic Sedimentary Rock)
Basalt with Phenocrysts (Porphyritic Basalt)
Porphyritic Basalt (primarily Plagioclase and Pyroxene)
Sandstone (Quartzose)
Arenite (Siliciclastic sedimentary rock)
Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Granodiorite
Granodiorite (Quartz-Feldspar-Biotite Plutonic Rock)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Pumice
Pumice (Amorphous volcanic glass)
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Basalt
Basalt
Sandstone
Arenite (composed primarily of SiO2)