Chalk
Micrite (primarily Calcium Carbonate, CaCO3)
sedimentary
Category
Anthropogenic (Man Made Industrial Deposit)
Browse anthropogenic (man made industrial deposit) specimens identified by the Rock Identifier community.
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Chert (Chert / Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Diamond
Carbon (C)
gemstone
Tumbled epidote-bearing rock (likely epidote–quartz–feldspar aggregate)
Epidote-rich metamorphic rock; minerals likely epidote (Ca₂(Al,Fe)₃Si₃O₁₂(OH), quartz, feldspar, and dark amphibole/biotite)
metamorphic
Diamond
Carbon (C)
mineral
Diamond in Kimberlite
Diamond in Kimberlite Matrix (Diamond: C, Kimberlite: complex Potassic Peridotite)
igneous
Galena (likely)
Galena, lead sulfide (PbS)
mineral
Diamond
Carbon (C)
mineral
Chert
Silicon dioxide (SiO2)
Sedimentary
Banded Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Silver (Native or Alloyed)
Ag (Argentum)
mineral
Dark gray rounded stone, possibly basalt or slag
Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or iron-rich industrial slag
igneous
Bumblebee Jasper
Anhydrite with Sulfur, Hematite, and Orpiment (SiO2/CaSO4 mixture)
sedimentary
Quartz (Milky or Smoky)
Silicon Dioxide (SiO2)
mineral
Iron Slag
Iron smelting byproduct (Glassy/vesicular silicate)
anthropogenic / industrial byproduct
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various additives
Man-made material (Anthropogenic 'mineraloid')
Sea Glass (Uranium/Vaseline Glass variant)
Silicon Dioxide (SiO2) with trace Uranium Oxide (U3O8)
man-made silicate (anthropogenic glass)
Siltstone Pebble
Siltstone (composed of microscopic quartz and clay minerals)
sedimentary
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
sedimentary
Chert / Jasper
Silicon Dioxide (SiO₂)
sedimentary
Metallic sulfide mineral specimen, likely pyrite
Pyrite (FeS₂), possibly a pyrite-rich sulfide aggregate
mineral
Sea Glass (Kelly Green)
Amorphous Silica (Silicon Dioxide with Iron/Chromium additives)
Anthropogenic specimen (Man-made material)
Note: Item is not a geological specimen
Polyester mesh and Ethylene-vinyl acetate (EVA) polymer
Synthetic / Anthropogenic Material
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Sandstone
Arenite (SiO2 based clastic rock)
sedimentary
Diamond (as featured in jewelry)
Diamond (C - pure carbon)
mineral
Fossil Shark Tooth
Lamniform (Mackerel Shark) fossil tooth, likely Otodus or Cretalamna
fossil
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
sedimentary
Banded Calcite or Travertine
Calcium Carbonate (CaCO3)
Sedimentary
Amethyst Cluster
Quartz (SiO2 with iron impurities)
gemstone
Small rounded pebble, likely quartz-rich stone
Indeterminate from photograph; possibly microcrystalline quartz (SiO₂) or a weathered silicate pebble
mineral
Grey Chalcedony
Silicon Dioxide (SiO2)
mineral
Tumbled chalcedony (likely moss or dendritic agate)
Microcrystalline quartz, SiO₂, with iron-oxide inclusions
mineral
Native copper (probable copper-rich mineral specimen)
Copper, Cu; possibly mixed with cuprite, malachite, and iron-oxide alteration minerals
mineral
Terrazzo (with Marble and Granite fragments)
Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates
sedimentary (man-made composite)
Diamond
Cubic carbon (C)
mineral
Banded Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
sedimentary
Dyed Chalcedony (Agate)
Silicon Dioxide (SiO2) with artificial pigment
mineral
Basalt
Basalt
igneous
Polished copper-bearing mineral specimen, likely malachite-rich copper ore
Malachite, Cu₂CO₃(OH)₂, possibly mixed with chrysocolla or limonite
mineral
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
mineral