Chert (specifically Flint or Jasper variant)
Microcrystalline quartz (SiO2)
Category
Browse sedimentary (secondary formation) specimens identified by the Rock Identifier community.
Chert (specifically Flint or Jasper variant)
Microcrystalline quartz (SiO2)
Dyed Pink Agate (or Dyed Quartzite)
Silicon dioxide (SiO2) with artificial pigment
Banded Jasper (Mookaite / Chert)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Carnelian (Chalcedony)
Silicon Dioxide (SiO2) with trace Iron Oxide
Coral Fossil
Scleractinia (Fossilized Coral)
Sandstone
Sedimentary Rock (Quartz arenite/Arkose)
Fossilized Brachiopod
Phylum Brachiopoda
Coal
Bituminous Coal / Anthracite
Sandstone Pebble
Sedimentary Rock (Quartzose Sandstone)
Fossilized Bivalve Shell
Class Bivalvia (fossilized)
Native copper-bearing rock (probable copper ore)
Native copper (Cu), likely with cuprite (Cu₂O), malachite (Cu₂CO₃(OH)₂), and iron-oxide matrix
Turquoise
Turquoise (Hydrated phosphate of copper and aluminium), CuAl6(PO4)4(OH)8·4H2O
Agate (Puddingstone style)
Silicon Dioxide (SiO2) with impurities
Turquoise (possible Dyed Howlite or Magnesite imitation)
CuAl6(PO4)4(OH)8·4H2O (Turquoise)
Native Copper (Penny specimen)
Native Copper (Cu)
Yellow Quartz (Chalcedony)
Silicon Dioxide (SiO2)
Beach Agate (Chalcedony)
Silicon Dioxide (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Agate (Common Chalcedony)
Silicon Dioxide (SiO2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Turquoise
Hydrate phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Limonite (Iron Ore)
Limonite (Iron oxide-hydroxide mixture, FeO(OH)·nH2O)
Dyed Blue Agate
Silicon Dioxide (SiO2)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Botryoidal Hematite
Hematite (Iron(III) oxide, Fe2O3)
Turquoise in Matrix
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Quartz (Chert/Chalcedony Variety)
Silicon Dioxide (SiO2)
Limonite (Iron Ore)
Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O
Calcite
Calcite (Calcium Carbonate, CaCO3)
Polished banded jasper (likely red jasper)
Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides; exact variety uncertain
Limestone with Fossil Fish Fragment
Calcite (CaCO3) containing a fossil teleost
Rounded river stone (likely iron-stained sandstone or siltstone)
Indeterminate ferruginous sandstone/siltstone; composition cannot be confirmed from the image
Tumbled river pebble, likely limestone or weathered chert
Indeterminate carbonate/siliceous pebble; possible micritic limestone or chert
Rounded river pebble, likely quartz-rich sandstone or quartzite
Indeterminate; probable quartz (SiO₂) with feldspar, iron-oxide staining, and minor lithic grains
Red Jasper
Silicon dioxide / Quartz (SiO2 (+Fe2O3))
Small red-brown mineral or rock fragment
Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide
Small rounded pebble
Indeterminate lithic grain; likely weathered sandstone, iron-stained quartz-rich rock, or a concretion
Botryoidal Chalcedony with Iron Staining
Microcrystalline Quartz (SiO2)
Quartz (Iron-stained / Orange Quartz)
Silicon Dioxide (SiO2)
Ferruginous Chert
Silicon dioxide with iron oxide impurities (SiO2 + Fe2O3)