Shale
Shale (Consolidated fine-grained clay/silt)
sedimentary
Category
Man Made Material, Not A Natural Rock Or Mineral Specimen
Browse man made material, not a natural rock or mineral specimen specimens identified by the Rock Identifier community.
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Chert (varietal Flint)
Microcrystalline quartz (SiO2)
sedimentary
Peacock Ore
Bornite (Cu5FeS4) or Chalcopyrite treated with acid
mineral
Diorite (Spotted)
Diorite (Intrusive igneous rock)
igneous
Colorless faceted gemstone (most likely synthetic cubic zirconia)
Cubic zirconia, ZrO₂ (likely synthetic); natural alternatives include quartz or diamond
gemstone
Rounded weathered pebble, likely sandstone or altered limestone
Indeterminate clastic carbonate/siliciclastic rock; exact identification requires a fresh surface and tests
sedimentary
Amethyst quartz crystal
Quartz, silicon dioxide (SiO₂), purple variety amethyst
mineral
Raw Agate (Rough Lake Superior Agate or Jasper-Chalcedony Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Brecciated Jasper
SiO2 (Silicon Dioxide)
sedimentary
Sandstone Pebble
Arenite (SiO2 primarily)
sedimentary
Green tourmaline crystal (likely elbaite)
Elbaite tourmaline, a complex borosilicate: Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
mineral
River Pebble (Siltstone / Sandstone Pebble)
Sedimentary Rock (Quartz, Feldspar, Clay Minerals)
sedimentary
Blue Dyed Agate Geode Slice
Chalcedony (Silicon Dioxide, SiO2) with artificial cobalt/iron-based dye
mineral
Quartz (likely tumbled or naturally water-worn)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Dyed Quartzite
Metamorphosed Quartz (SiO2) with synthetic pigment
metamorphic
Sandstone (Graywacke type)
Clastic Sedimentary Rock (Lithic Sandstone)
sedimentary
Sandstone with Iron Weathering
Quartz Arenite / Weathered Sandstone
sedimentary
Yellow Quartz (or Citrine Quartz)
Silicon Dioxide (SiO2)
mineral
Blue Sphalerite (likely dyed or treated Druzy Quartz/Agate)
Zinc Sulfide (ZnS) or Silicon Dioxide (SiO2) with trade-name enhancement
Mineral
Gravel (Crushed Stone Aggregates)
Mixed Siliciclastic / Carbonate Aggregate
sedimentary
Milky quartz fragment
Quartz (silicon dioxide, SiO₂)
mineral
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2 with minor Fe2O3)
sedimentary
Aventurine
Aventurine Quartz (SiO2 with inclusions)
metamorphic
Smoky Quartz
Silicon Dioxide (SiO2) with trace aluminum and irradiation
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Polished dendritic jasper or agate slab
Microcrystalline quartz (SiO₂), likely jasper with chalcedony and iron/manganese dendrites
mineral
Chert Pebble
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Gravel and Pavement Aggregates
Unconsolidated rock fragments / detrital sediments
sedimentary
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Vesicular volcanic scoria (likely weathered basaltic scoria)
Scoria; chiefly vesicular basalt, composed mainly of plagioclase, pyroxene, and iron-rich glass
igneous
Sandstone (Greywacke/Lithic Sandstone)
Clastic Sedimentary Rock (Lithic Sandstone)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Grooved Maun Ball (Maul/Hammerstone-like Concretion)
Calcareous/Ferruginous Concretion in Sandstone Matrix
sedimentary
Ferrochrome Slag
Industrial Glassy Slag (Fe-Cr alloy byproduct)
Antropogenic (Man-made industrial byproduct)
Ferrous Slag (Iron Smelting By-product)
Fused Siliceous Slag
Anthropogenic Material (Man-made Rock)
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Diamond
Diamond (C)
mineral
Polished yellow jasper or opaque chalcedony bead
Microcrystalline quartz (SiO₂), likely iron-oxide-stained jasper
mineral
Sandstone
Arenite (lithic or quartz sandstone)
sedimentary
Sandstone
Arenite (predominantly SiO2)
sedimentary
Moss agate bracelet
Chalcedony (microcrystalline quartz, SiO₂) with chlorite/amphibole inclusions
gemstone
Thulite in Matrix
Pink Zoisite - Ca2Al3(SiO4)3(OH)
metamorphic