Rock Identifier

Category

Sedimentary (Secondary Formation)

Browse sedimentary (secondary formation) specimens identified by the Rock Identifier community.

Quartz geode (Microcrystalline and crystalline quartz, SiO₂, likely with chalcedony and iron-oxide staining) — mineral

Quartz geode

Microcrystalline and crystalline quartz, SiO₂, likely with chalcedony and iron-oxide staining

Quartzite Pebble (Meta-quartzite) — metamorphic

Quartzite Pebble

Meta-quartzite

Fossilized Dinosaur Bone (Perineralized Bone (Fluorapatite/Quartz replacement)) — fossil

Fossilized Dinosaur Bone

Perineralized Bone (Fluorapatite/Quartz replacement)

Small pale stone, possibly quartz or limestone (Indeterminate from image; likely quartz (SiO₂) or calcite-rich limestone (CaCO₃)) — mineral

Small pale stone, possibly quartz or limestone

Indeterminate from image; likely quartz (SiO₂) or calcite-rich limestone (CaCO₃)

Iron-rich rock, possibly hematite-rich ironstone (Likely hematite (Fe₂O₃) or a hematite-bearing ironstone; the photo is insufficient for a definitive identification) — mineral

Iron-rich rock, possibly hematite-rich ironstone

Likely hematite (Fe₂O₃) or a hematite-bearing ironstone; the photo is insufficient for a definitive identification

Fine-grained gray-green rock, possibly slate or phyllite (Indeterminate from the image; likely low-grade metamorphosed mudstone (slate/phyllite)) — metamorphic

Fine-grained gray-green rock, possibly slate or phyllite

Indeterminate from the image; likely low-grade metamorphosed mudstone (slate/phyllite)

Rounded beach pebble, likely fine-grained sandstone or siltstone (Indeterminate sedimentary lithic fragment; exact identification requires examination) — sedimentary

Rounded beach pebble, likely fine-grained sandstone or siltstone

Indeterminate sedimentary lithic fragment; exact identification requires examination

Small brown mineral fragment (Unidentified; the image lacks enough detail for a reliable species-level identification) — mineral

Small brown mineral fragment

Unidentified; the image lacks enough detail for a reliable species-level identification

Small pale stone, likely quartzite or limestone fragment (Indeterminate; possible quartzite (mostly SiO₂) or calcitic limestone (CaCO₃)) — metamorphic or sedimentary

Small pale stone, likely quartzite or limestone fragment

Indeterminate; possible quartzite (mostly SiO₂) or calcitic limestone (CaCO₃)

metamorphic or sedimentary

Unidentified polished stone fragments (Indeterminate; likely mixed lapidary specimens, possibly jasper, agate, or quartz-bearing rock) — mineral

Unidentified polished stone fragments

Indeterminate; likely mixed lapidary specimens, possibly jasper, agate, or quartz-bearing rock

Fossiliferous Limestone (Carbonate sedimentary rock (CaCO3) with bioclasts) — sedimentary

Fossiliferous Limestone

Carbonate sedimentary rock (CaCO3) with bioclasts

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Basalt with Quartz Veining (Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins) — igneous

Basalt with Quartz Veining

Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins

Clear Quartz (Quartz (Silicon Dioxide, SiO2)) — Mineral

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Unidentifiable embedded dark fragment (Indeterminate; possibly a dark silicate mineral or lithic inclusion) — mineral

Unidentifiable embedded dark fragment

Indeterminate; possibly a dark silicate mineral or lithic inclusion

Weathered iron-rich rock, possibly limonite-bearing basalt or ironstone (Uncertain; likely Fe-oxide/hydroxide–stained mafic rock (hematite Fe₂O₃, goethite FeO(OH), and silicates)) — igneous

Weathered iron-rich rock, possibly limonite-bearing basalt or ironstone

Uncertain; likely Fe-oxide/hydroxide–stained mafic rock (hematite Fe₂O₃, goethite FeO(OH), and silicates)

Mookaite Jasper (SiO2) — Sedimentary

Mookaite Jasper

SiO2

Rounded gray river pebble, likely fine-grained sandstone or siltstone (Indeterminate clastic sedimentary rock; possibly quartz-rich sandstone or siltstone) — sedimentary

Rounded gray river pebble, likely fine-grained sandstone or siltstone

Indeterminate clastic sedimentary rock; possibly quartz-rich sandstone or siltstone

Sandstone (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone

Clastic sedimentary rock (primarily SiO2)

Sandstone (Arenite (SiO2 primarily)) — sedimentary

Sandstone

Arenite (SiO2 primarily)

Concretionary Sandstone (Clastic Sedimentary Rock (Sandstone with secondary mineral cementation)) — sedimentary

Concretionary Sandstone

Clastic Sedimentary Rock (Sandstone with secondary mineral cementation)

Chrysocolla on Quartz (Chrysocolla (Cu2−xAlx(H2−xSi2O5)(OH)4·nH2O) often associated with Quartz (SiO2)) — mineral

Chrysocolla on Quartz

Chrysocolla (Cu2−xAlx(H2−xSi2O5)(OH)4·nH2O) often associated with Quartz (SiO2)

Rhodochrosite (Manganese carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese carbonate (MnCO3)

Baltic Amber (Succinite (Fossilized Tree Resin)) — fossil

Baltic Amber

Succinite (Fossilized Tree Resin)

Limonite (Iron Ore) (Hydrated ferric oxide (FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Hydrated ferric oxide (FeO(OH)·nH2O)

Druzy Chalcedony (Agate Geode) (Silica (SiO2) - Cryptocrystalline Quartz with druzy macrocrystalline quartz) — mineral

Druzy Chalcedony (Agate Geode)

Silica (SiO2) - Cryptocrystalline Quartz with druzy macrocrystalline quartz

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Pink Opal (Hydrated silica (SiO2 "n H2O)) — mineral

Pink Opal

Hydrated silica (SiO2 "n H2O)

Quartz Geode (Silicon Dioxide (SiO2)) — mineral

Quartz Geode

Silicon Dioxide (SiO2)

Botryoidal Quartz Cluster (Druzy Stalactitic Quartz) (Silicon Dioxide (SiO2)) — mineral

Botryoidal Quartz Cluster (Druzy Stalactitic Quartz)

Silicon Dioxide (SiO2)

Agate (or Chalcedony pebble) (Silicon Dioxide (SiO2)) — mineral

Agate (or Chalcedony pebble)

Silicon Dioxide (SiO2)

Banded Agate / Jasper (Chert Pebble) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Banded Agate / Jasper (Chert Pebble)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Turquoise (CuAl6(PO4)4(OH)8·4H2O) — mineral

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Quartz (Citrine or Iron-Stained variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Citrine or Iron-Stained variety)

Silicon Dioxide (SiO2)

Ferruginous Quartz (Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions) — mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Variscite in Matrix (Variscite (AlPO4 · 2H2O)) — mineral

Variscite in Matrix

Variscite (AlPO4 · 2H2O)

Ferruginous Quartz (Silicon Dioxide (SiO2) with Iron Oxide inclusions) — mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Limonite with Hematite (Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)) — mineral

Limonite with Hematite

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Carnelian (SiO2 (Silicon Dioxide), a variety of Chalcedony) — mineral

Carnelian

SiO2 (Silicon Dioxide), a variety of Chalcedony

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Agate (Chert/Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Agate (Chert/Chalcedony)

Silicon Dioxide (SiO2)

Howlite (Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)) — mineral

Howlite

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)