Tumbled dark stone, possibly chert or basalt
Indeterminate; likely fine-grained basalt (plagioclase–pyroxene) or microcrystalline chert (quartz, SiO₂)
Category
Browse man made composite (lithified equivalent of sedimentary) specimens identified by the Rock Identifier community.
Tumbled dark stone, possibly chert or basalt
Indeterminate; likely fine-grained basalt (plagioclase–pyroxene) or microcrystalline chert (quartz, SiO₂)
Flint
Silicon dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Coquina and Oyster Fossil Rock
Coquina limestone (Calcium Carbonate, CaCO3) containing fossilized Crassostrea / bivalve shells
Chert (Flint)
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
Sandstone
Arenite
Coquina
Coquina (Biogenic Limestone / CaCO3)
Red Sandstone
Arenite (Ferruginous Sandstone)
Banded Slate (Lithified Mudstone)
Low-grade Metamorphosed Mudstone / Slate
Chalcedony (Agate / Jasper Specimen)
Silicon Dioxide (SiO2)
Coquina
Bioclastic Limestone
Coquina
Bioclastic Limestone
Slate
Metamorphic Pelitic Rock
Jasper / Chert (Red)
Cryptocrystalline quartz (SiO2)
Chert (Flint nodule)
Chert (SiO2)
Weathered fossiliferous sandstone or mudstone cobble
Lithified siliciclastic sediment; the raised curved feature may be a trace fossil or shell impression
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert
Chert (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert Arrowhead (Jasper)
Chert (Cryptocrystalline Quartz, SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Flint
SiO2 (Cryptocrystalline Quartz)
Brecciated Jasper
Brecciated Jasper (Microcrystalline Quartz / SiO2)
Sandstone
Arenite
Iron-stained quartz-rich rock, possibly jasper or chert
Microcrystalline quartz (SiO₂) with iron oxides/hydroxides
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Blue Slag Glass
Amorphous Silica (Byproduct of smelting)
Blue Goldstone
Aventurine Glass (SiO2 with Cobalt/Copper inclusions)
Synthetic Resin (Artificial Specimen)
Polyurethane or Polyester Resin
Slag Glass (Cullet)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Slag (Anthropogenic Glass/Iron byproduct)
Ferro-silicate Slag
Artisanal Glass Beads (Simulated Goldstone or Aventurine Glass)
Silicon Dioxide (SiO2) with metallic inclusions
Chert Nodule
Microcrystalline Quartz (SiO2)
Blue slag glass or dyed glass-like industrial material
Amorphous silicate glass; likely copper-bearing blue slag, but possibly colored man-made glass
Chert
Microcrystalline silica (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Black Limestone with Calcite Veining
Bituminous Limestone (CaCO3 with Organic Carbon inclusions)
Chert (Chert / Flint Variety)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
White Marble
Recrystallized Calcite (CaCO3)