Chert (Brecciated Chert)
Silicon Dioxide (SiO2)
Category
Browse organic (non rock) specimens identified by the Rock Identifier community.
Chert (Brecciated Chert)
Silicon Dioxide (SiO2)
Opalite
Synthetic Opalised Glass
Apache Tear
Obsidian (Hydrated Silica Rich Volcanic Glass)
Amber
Succinite (a specific common type) or Fossilized Tree Resin (C10H16O)
Note on Image Identification: Textile
N/A (Anthropogenic material)
Black Obsidian
Obsidian (Volcanic glass), 70–75% SiO2
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Piddock-bored Mudstone
Lutite (Siltstone or Mudstone) with Pholad borings
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Granodiorite (foreground) and Rose Quartz (background)
Granodiorite / Quartz (SiO2)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Granite
Felsic Plutonic Rock (primarily SiO2)
Basalt (tumbled/river-worn)
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
Quartzite / Sandstone / Chert Mix
Silicon Dioxide (SiO2)
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
Basalt
Basalt (Mafic Volcanic Rock)
Obsidian
Obsidian (Volcanic Glass, complex silicate)
Man-made Synthetic Material (Costume Faux Fur)
Synthetic Polymer (Polyester/Acrylic)
Quartzite
Silicon Dioxide (SiO2)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Chert (Yellow/Tan Variety)
Chert (SiO2)
Fossilized Shell in Limestone
Bivalve fossil (CaCO3) in Carbonate Sedimentary Rock
Man-made Blank Ammunition (Brass)
CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
Shale or Slaty Mudstone
Argillaceous sedimentary rock
Metaconglomerate
Protolith: Conglomerate (comprising SiO2, Al2O3, etc.)
Basalt
Basalt (Igneous Volcanic Rock)
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
Quartzite River Rock
Quartzite (primarily SiO2)
Snowflake Obsidian
Volcanic glass with Spherulite inclusions (SiO2)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Quartzite
Quartzite (primarily SiO2)
Herkimer Diamond
Quartz (Silica - SiO2)
Common Opal with Host Rock
Opal (Hydrated silica, SiO2·nH2O)
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)