Blue Calcite
Calcium Carbonate (CaCO3)
Category
Browse sedimentary specimens identified by the Rock Identifier community.
Blue Calcite
Calcium Carbonate (CaCO3)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and clay impurities
Orange Calcite (likely polished specimen)
Calcite
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Pyrite
Iron Disulfide (FeS2)
Pyrite Nodules / Weathered Pyrite
Iron Sulfide (FeS2)
Banded gneiss (likely garnet-biotite or quartz-feldspar gneiss)
Gneiss; predominantly quartz (SiO₂), feldspar, and dark biotite/amphibole
Banded gneiss (likely biotite-bearing)
Gneiss; quartz–feldspar–mica assemblage, with possible iron-oxide staining
Felsic gneiss, likely granitic gneiss
Quartz–feldspar–mica gneiss; commonly quartz + plagioclase/K-feldspar + biotite or hornblende
Granite
Felsic intrusive igneous rock
Banded Iron Formation
Banded Iron Formation (BIF)
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
Limestone (or Sandstone)
Calcium Carbonate (CaCO3) / Silica (SiO2)
Sandstone with Quartz Sphere
Arenite (SiO2-rich sedimentary rock) with Quartzite/Rose Quartz sphere
Sandstone
Clastic Sedimentary Rock (Quartz arenite)
Sandstone
Clastic sedimentary rock (Quartz arenite)
Sandstone (likely Arkose or Lithic)
Clastic sedimentary rock (primarily SiO2)
Raw selenite (gypsum)
Gypsum, CaSO₄·2H₂O; translucent variety selenite
Quartz
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Quartz (Variety: Agate / Chalcedony)
Silicon Dioxide (SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Sandstone
Quartzose Sandstone (Sedimentary Rock)
Sandstone Pebble
Sedimentary Rock (Quartzose Sandstone)
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sandstone Pebble
Sedimentary Rock (Quartzose Sandstone)
Sandstone Pebble
Sedimentary Rock (Quartz Arenite)
Conglomerate (Red Sandstone variety)
Clastic Sedimentary Rock (Conglomeratic Sandstone)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Limonite (Iron Stone Concretion)
Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O
Chert (Common Opal/Jasper variety)
Microcrystalline Quartz (SiO2) with hydration
Banded sandstone (likely quartzitic sandstone)
Quartz-rich sandstone; predominantly quartz (SiO₂) with iron-oxide cement and minor feldspar/clay
Conglomerate
Conglomerate Rock
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)
Chalk / Sedimentary Limestone
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
Sedimentary Pebble (Sandstone)
Clastic Sedimentary Rock (SiO2 dominant)
Chalk (Sedimentary Limestone)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
Bivalve Fossil (Shell-bearing Sedimentary Rock)
Class Bivalvia (Phylum Mollusca) within a Calcarenite/Sandstone matrix
Jasper
Microcrystalline Quartz (SiO2)
Quartz Crystal
Silicon Dioxide (SiO2)