Sea Glass
Amorphous Silicon Dioxide (Man-made glass weathered by nature)
mineral
Category
Man Made Rock (Sedimentary Analogue)
Browse man made rock (sedimentary analogue) specimens identified by the Rock Identifier community.
Learn about Man Made Rock (Sedimentary Analogue) in the encyclopedia
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Flint
Silicon dioxide (SiO2)
sedimentary
Beach Pebble (Chalcedony / Chert)
Silicon Dioxide (SiO2)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3)
sedimentary
Chert
Microcrystalline quartz (SiO2)
sedimentary
Siltstone Pebble
Siltstone (composed of microscopic quartz and clay minerals)
sedimentary
Chert
Microcrystalline quartz (SiO2)
sedimentary
Coquina / Fossiliferous Limestone
Calcareous bioclastic sedimentary rock (CaCO3)
sedimentary
Petoskey Stone
Hexagonaria percarinata (Fossilized Coral)
sedimentary
Chert (Flint)
Chert (Cryptocrystalline Silica, SiO2)
sedimentary
Sandstone (likely Quartzose Sandstone)
Arenite
sedimentary
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Man-made Object/Uncertain Mineral
Tumbled brown chalcedony (likely jasper or agate)
Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining
mineral
Chert (and Agate/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Crinoid Fossil in Limestone
Crinoid columnal (Class Crinoidea) in biomicrite
fossil
Mica Schist
Mica Schist (principally Biotite/Muscovite, Quartz, and Feldspar)
metamorphic
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Sea Glass
Amorphous silicon dioxide (Man-made glass weathered by nature)
mineral
Chert (Black Flint)
Silicon Dioxide (SiO2)
sedimentary
Basalt
Basalt
Igneous
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
sedimentary
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
sedimentary
Chalk
Carbonate rock (mainly CaCO3)
sedimentary
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
sedimentary
Bivalve Fossil (Shell Fragment)
Class Bivalvia (Calcium Carbonate - CaCO3)
sedimentary
Opalite (a synthetic glass, often confused with Opal)
Silicon dioxide glass (SiO2nH2O, for natural opal)
Synthetic (glass)
Green Glass Slag
Amorphous Silicon Dioxide (SiO2) with metal oxide impurities
mineraloid (man-made)
Coquina and Oyster Fossil Rock
Coquina limestone (Calcium Carbonate, CaCO3) containing fossilized Crassostrea / bivalve shells
fossil
Coal (Anthracite / Bituminous)
Organic Sedimentary Rock (Carbon-based)
sedimentary
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Shark Tooth
Carcharocles sp. or Striatolamia sp. (Phosphate/Carbonate mineralized Hydroxyapatite)
sedimentary
Chert (River Siltstone/Quartzite type)
Microcrystalline Quartz (SiO2)
sedimentary
River Pebbles (Chert and Quartzite)
Sedimentary Clastic Rock (Silica-rich)
sedimentary
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
sedimentary
Banded Sandstone
Arenite with Liesegang banding
sedimentary
Chert (varietal Flint)
Microcrystalline quartz (SiO2)
sedimentary
Sandstone Pebble
Ferruginous Sandstone (SiO2 with Fe2O3)
sedimentary
Chert (Jasper / Quartz pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Blue slag glass or dyed glass-like industrial material
Amorphous silicate glass; likely copper-bearing blue slag, but possibly colored man-made glass
mineral
Banded Chert (River Stone)
Silicon Dioxide (SiO2)
sedimentary