Quartz Grain
Silicon Dioxide (SiO2)
Category
Browse sedimentary (primary) with artificial modification specimens identified by the Rock Identifier community.
Quartz Grain
Silicon Dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Coal
Carbonaceous sedimentary rock
Green Aventurine
Silicon Dioxide with Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Limestone Cobble
Sedimentary Calcium Carbonate (CaCO3)
Hematite
Iron(III) oxide (Fe2O3)
Magnetic Sand Grain / Magnetite Pellet
Magnetite (Fe3O4)
Hematite
Iron(III) oxide (Fe2O3)
Hematite
Hematite (Fe2O3)
Hematite
Iron(III) oxide (Fe2O3)
Sandstone with Quartz Vein
Arenite with Quartz (SiO2) protrusion
Chert Pebble
Microcrystalline Quartz (SiO2)
Blue Aura Quartz
Silicon Dioxide (SiO2) with metallic vapor coating
Citrine
Silicon dioxide (SiO2)
Banded Sandstone (River Pebble)
Arenite (SiO2 primarily)
Chert / Flint
SiO2 (Silicon Dioxide)
Red Tiger's Eye
Silicified Crocidolite (Quartz pseudo-morph after Crocidolite), SiO2
Limestone
Sedimentary Calcite (CaCO3)
Pink Agate
Chalcedony (SiO2)
Limestone
Sedimentary rock composed primarily of Calcite (CaCO3)
Gray Limestone
Carbonate rock (CaCO3)
Granular Sandstone
Arenite (variable composition, primarily SiO2)
Limestone (Micritic)
Sedimentary rock mainly composed of Calcium Carbonate (CaCO3)
Sandstone (Greywacke/Siltstone variant)
Arenite / Wacke (SiO2 with diverse mineral inclusions)
Limestone
Carbonate rock (CaCO3)
Limestone (River Pebble)
Calcium Carbonate (CaCO3)
Bauxite
AlOx(OH)3-2x (mixture of Gibbsite, Boehmite, and Diaspore)
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
White quartz pebble
Quartz (silicon dioxide, SiO₂)
Tumbled quartz-rich pebble, possibly calcite or quartzite
Most likely microcrystalline quartz (SiO₂); carbonate identification would require testing
Hematite Nodule
Iron oxide, Fe2O3
Sandstone (Quartzite-rich River Cobble)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Chert
Microcrystalline quartz (SiO2)
Chert
Microcrystalline quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Flint
Silicon dioxide (SiO2)
Banded Chert
Silicon Dioxide (SiO2)
Chert (often called Flint when found in chalk)
Microcrystalline Quartz (SiO2)
Chert (specifically Flint)
Silicon Dioxide (SiO2)
Limestone with Calcite Crust
Sedimentary Calcium Carbonate (CaCO3)