Limestone (or Sandstone)
Calcium Carbonate (CaCO3) / Silica (SiO2)
Category
Browse organic (mineraloid) specimens identified by the Rock Identifier community.
Limestone (or Sandstone)
Calcium Carbonate (CaCO3) / Silica (SiO2)
Sandstone (with Moss)
Quartz Arenite / Sandstone
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
Pyrite
Iron Sulfide (FeS2)
Limestone (Carved Statue)
Calcium Carbonate (CaCO3)
Poppy Jasper
Microcrystalline Quartz (SiO2) with mineral inclusions
Jasper
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone
Biogenic Sedimentary Rock (primarily CaCO3)
Green Chert
Microcrystalline Quartz (SiO2)
Chert (specifically Flint or Nodular Chert)
Silicon dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Flint (Chert Node)
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Arrowhead Artifact)
Chert (SiO2)
Chert (and Chalcedony)
Microcrystalline Quartz (SiO2)
Pyrite Geode
Iron Disulfide (FeS2)
Chert (Jasper)
Silicon Dioxide (SiO2)
Chert (often called Flint)
Silicon Dioxide (SiO2)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclastic Inclusions
Fossil tooth
Mineralized vertebrate tooth; exact animal and species cannot be determined from the image
Black Pearl (Tahitian Type)
Aragonite / Pinctada margaritifera (CaCO3 + Conchiolin)
Dendritic Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
Red Coral
Corallium rubrum
Chert
Chert (Microcrystalline Quartz, SiO2)
Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
Desert Rose Fragment (Atypical) / Weathered Chert
Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy
Amber (possibly rough amber)
Fossilized tree resin; chemically a complex organic mixture, commonly classified as succinite when Baltic in origin
Chert (likely flint)
Microcrystalline quartz (SiO₂), chiefly chalcedony and quartz
Chert (likely flint), possibly chalcedony-rich
Microcrystalline quartz, SiO₂ (quartz/chalcedony)
Weathered iron-rich rock, likely ferruginous sandstone or lateritic concretion
Iron-oxide–cemented sandstone; commonly dominated by quartz (SiO₂), goethite (FeO(OH)) and hematite (Fe₂O₃)
Graphitic schist (probable)
Graphite-bearing mica schist; chiefly quartz, mica, and graphite
Amber
Succiniferous fossil resin (C10H16O)
Amber
Succinite (Fossilized Tree Resin)
Concretion
Septarian or Siderite Concretion
Chert Concretion
Sedimentary Cryptocrystalline Quartz (SiO2)
Tumbled moss agate
Chalcedony (microcrystalline quartz, SiO₂) with moss-like inclusions
Amber
Fossilized Tree Resin
Amber
Succinite (Fossilized Tree Resin)
Banded Siltstone Pebble
Siltstone (primarily SiO2, Al2O3, Fe2O3)
Amber (Copal)
Fossilized Tree Resin (C10H16O)
Amber
Succinite (Resinite), C10-H16-O