Chert (Flint)
Microcrystalline Quartz (SiO2)
Category
Browse anthropogenic (man made material mimicking sedimentary rock) specimens identified by the Rock Identifier community.
Chert (Flint)
Microcrystalline Quartz (SiO2)
Man-made Crystal (Lead Glass)
Lead oxide-doped Silica Glass (approx. SiO2 + PbO)
Coal (Bituminous Coal)
Caustobiolith / Sedimentary Rock
Brecciated jasper (likely red-and-cream jasper)
Jasper, an opaque microcrystalline variety of quartz; primarily cryptocrystalline SiO₂ with iron-oxide staining and possible chalcedony/quartz veining
Gravel / Crushed Stone
Aggregate (mixed mineral rock fragments)
Chert (Flint)
Silicon Dioxide (SiO2)
Bivalve Fossil (Shell Fragment)
Class Bivalvia (Calcium Carbonate - CaCO3)
Sandstone
Arenite (SiO2 dominant)
Coquina
Biogenic Limestone (Calcite, CaCO3)
Chert / Flint
Silicon Dioxide (SiO2)
Jasper (Iron-rich Chalcedony)
Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)
Basalt
Basalt
White Marble
Recrystallized Calcite (CaCO3)
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
Sandstone (Ferruginous)
Arenite (with Iron Oxide)
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Quartz (Microcrystalline/Chert)
Silicon Dioxide (SiO2)
Chert
Microcrystalline Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 principal)
Sandstone (Water-worn Cobble)
Arenite (SiO2 with CaCO3 or Fe2O3 cement)
Limestone (Weathered)
Sedimentary Carbonate Rock (CaCO3)
Coquina
Coquina (Biogenic Limestone / CaCO3)
Sandstone
Sandstone (clastic sedimentary rock, predominantly SiO2)
Chert (with nodule)
Microcrystalline Quartz (SiO2)
Coquina
Biogenic Limestone (Coquina)
Coquina / Fossiliferous Limestone
Coquina (composed primarily of Calcium Carbonate / CaCO3)
Banded Gneiss
Gneiss (Foliated Metamorphic Rock)
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3)
Swirled Agate Bead
Silicon Dioxide (SiO2)
Chert (often called Flint or Jasper)
Microcrystalline Quartz (SiO2)
Red Slag Glass (Cullet)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Rainbow Hematite (Man-made/Treated)
Tumbled Hematite with Titanium/Anodized coating (Iron(III) oxide, Fe2O3)
Mudstone
Argillite / Siliciclastic sedimentary rock
Limestone
Sedimentary Rock (Primarily CaCO3)
Red Sandstone
Arenite (Ferruginous Sandstone)
Tumbled brown chalcedony (likely jasper or agate)
Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Mica Schist
Mica Schist (principally Biotite/Muscovite, Quartz, and Feldspar)
Diorite
Diorite (Intermediate intrusive igneous rock)
Chert (Nodule)
Microcrystalline Quartz (SiO2)