Limestone
Calcium Carbonate (CaCO3)
sedimentary
Category
Industrial Byproduct (Anthropogenic Material)
Browse industrial byproduct (anthropogenic material) specimens identified by the Rock Identifier community.
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Queen Conch Shell (Biogenic Calcium Carbonate)
Aliger gigas (synonym Strombus gigas); Composition: Aragonite (CaCO3)
mineral
Diamond
Diamond (pure Carbon, C)
mineral
Diamond (in Jewelry)
Carbon (C)
mineral
Crushed Stone (Gravel/Aggregates)
Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)
sedimentary and igneous (mixed)
Opalite
Man-made glass (traditionally simulated Opal)
mineral
Diamond (or Diamond Simulant)
Carbon (C) or Zirconium dioxide (ZrO2) for CZ
gemstone
Agate
Silicon Dioxide (Chalcedony), SiO2
gemstone
Diamond
C (Carbon)
mineral
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (Lithic arenite / Quartz arenite)
sedimentary
Rough Diamond
Diamond (C)
mineral
Diamond (or Cubic Zirconia simulant)
Carbon (C) or Zirconium Dioxide (ZrO2)
mineral
Likely petrified wood or silicified fossil fragment
Silicified wood; predominantly microcrystalline quartz (SiO₂)
fossil
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Hematite/Limonite inclusions
mineral
Tumbled sodalite (probable)
Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂
mineral
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Peridot (Olivine)
Olivine ((Mg, Fe)2SiO4)
mineral
Sandstone
Arenite (Sandstone)
sedimentary
Basalt Pebble
Basalt (Mafic volcanic rock)
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Coal (Bituminous)
Organic sedimentary rock primarily consisting of carbon (C)
sedimentary
Sandstone (Weathered Pebble)
Arenite (SiO2 primarily)
sedimentary
Sandstone
Arenite (specifically Quartz Arenite)
sedimentary
Coal (Anthracite or Bituminous)
Lithified plant matter (Carbon)
sedimentary
Fossiliferous Limestone with Crinoid Stem fragment
Calcite (CaCO3) containing Crinoidea fossils
sedimentary
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
sedimentary
Sea Shell Fragment (Calcium Carbonate)
Aragonite / Calcite (CaCO3)
mineral
Quartzite Pebbles
Quartzite (SiO2)
metamorphic
Mudstone
Lutylite (group of fine-grained sedimentary rocks)
sedimentary
Diamond (or Diamond Simulant/Cubic Zirconia)
Carbon (C) - if diamond, or Zirconium dioxide (ZrO2) - if Cubic Zirconia
mineral
Small rounded pebble
Indeterminate lithic grain; likely weathered sandstone, iron-stained quartz-rich rock, or a concretion
sedimentary
Diamond
Diamond (pure carbon, C)
mineral
Rough Diamond
Diamond (pure Carbon, C)
mineral
Tumbled blue stone, likely sodalite
Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂; possibly blue calcite or dyed material
mineral
Likely tumbled jasper or iron-rich chert
Microcrystalline quartz (SiO₂), potentially hematite/goethite-bearing
mineral
Quartz with Iron Oxide Staining
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Sandstone
Arenite (compositionally various, primarily SiO2)
sedimentary
Peridot (Olivine)
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
mineral
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
sedimentary