Limestone
Calcium Carbonate (CaCO3)
Category
Browse sedimentary rock (technically chert, a microcrystalline quartz) specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
Sandstone (likely River-tumbled Picture Sandstone)
Arenite (predominantly SiO2 with iron oxide impurities)
Amethyst (Geode/Druzy)
Silicon Dioxide (SiO2) with iron impurities
Crazy Lace Agate
Banded Chalcedony (Microcrystalline Quartz, SiO2)
Sandstone Beach Pebble
Clastic sedimentary rock (SiO2 with iron oxide cement)
Banded Gneiss (with Quartz Vein)
Gneiss (Metamorphic rock of varying mineralogy)
Sandstone (Ferruginous/Banded)
Clastic Terrigenous Sandstone (SiO2 with Fe2O3 cement)
Zebra Jasper
Tumbled Opaque Chalcedony (SiO2)
Quartzite River Stone
Quartzite (SiO2)
Jasper with Agate Inclusions
Jasper (Silicon Dioxide, SiO2) with Chalcedony/Agate
Quartz Druzy Geode Fragment
Silicon Dioxide (SiO2)
Sandstone (with possibly iron oxides and other minerals)
Sandstone
Sandstone with Calcite Vein
Clastic sedimentary rock (primarily SiO2) with Calcium Carbonate (CaCO3) infilling
Tumbled Stones (various)
Mixed Silica-based Minerals (primarily Quartz and Chalcedony)
Herkimer Diamond (Quartz Crystal)
Silicon Dioxide (SiO2)
Agate
Cryptocrystalline Quartz (SiO2)
Green Aventurine
Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
Quartz (Common Milky Quartz)
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Limestone Pebble
Calcium Carbonate (CaCO3)
Sandstone (Greywacke)
Arenite / Wacke (Mainly SiO2 with various lithic fragments)
Yellow Ochre / Limonite
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Carnelian
Carnelian (Microcrystalline Quartz, SiO2)
Pink Dyed Agate
Silicon Dioxide (SiO2) - Variety Agate
Limestone (specifically Dolomitic/Crystalline Limestone)
Sedimentary Carbonate Rock (CaCO3 / CaMg(CO3)2)
Sandstone (Greywacke/Lithic Sandstone)
Arenite (composed primarily of SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Limestone
Sedimentary rock composed of Calcium Carbonate (CaCO3)
Fossilized Shell in Limestone
Bivalve fossil (CaCO3) in Carbonate Sedimentary Rock
Geode (Quartz)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (composed primarily of SiO2)
Quartzite (River-worn pebble)
Quartzite (Mainly SiO2)
Banded Flint / Chert
Silicon Dioxide (SiO2)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
Chalcedony (specifically Agate or Carnelian pebble)
Chalcedony (Microcrystalline Quartz, SiO2)
Gneiss (Banded Gneiss)
Gneiss
Green Jasper
Silicon Dioxide (SiO2) with iron silicate inclusions