Crinoid Stem Columns (Fossil)
Crinoidea (Class); often composed of the mineral Calcite (CaCO3)
Category
Browse marble specimens identified by the Rock Identifier community.
Crinoid Stem Columns (Fossil)
Crinoidea (Class); often composed of the mineral Calcite (CaCO3)
Diamond
Carbon (C)
Diamond (Rough)
Diamond (Carbon, C)
Basalt
Mafic volcanic rock (Silicon dioxide 45-52%)
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
Fossilized Coral (Honeycomb Coral)
Favosites (extinct genus of tabulate corals), CaCO3 (Calcium Carbonate)
Conglomerate (Puddingstone)
Conglomerate (specifically, clastic sedimentary rock)
Chert
Microcrystalline Quartz (SiO2)
Chert (Black Chert/Flint)
Silicon Dioxide (SiO2)
Flint
Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)
Chert
Chert (microcrystalline quartz)
Jasper (Mookaite style)
Jasper (Silica-rich Microcrystalline Quartz, SiO2)
Chert (Flint variety)
Chert (SiO2)
Chert (Flint)
Microcrystalline quartz (SiO2)
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Chalcedony mix)
Chert (Field Stone)
Microcrystalline Quartz (SiO2)
Peridot
Olivine (Mg, Fe)2SiO4
Fossiliferous Limestone (Murchisonia/Gastropod Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (Hag Stone / Hole Stone)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Diamond
Carbon (C), specifically a solid form of the element carbon with atoms arranged in a crystal structure called diamond cubic.
Amber
Fossilized tree resin (not a true mineral as it is organic and amorphous); Chemical formula is highly variable, but often approximated as C10H16O.
Chert (Jasper/Agate variety)
Silicon Dioxide (SiO2)
Diatomite
Diatomaceous Earth (mostly SiO2·nH2O)
Quartzite Pebbler
Quartzite (mainly SiO2)
Petoskey Stone
Hexagonaria percarinata
Coquina / Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
Land Snail Shell
Gastropoda (Calcium Carbonate, CaCO3)
Chert
Chert (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Pearl
Calcium carbonate (CaCO3) as Aragonite or Calcite
Chalk
Carbonate rock (mainly CaCO3)
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Limestone
Limestone (Calcium Carbonate, CaCO3)
Chert (Flint)
Silicon Dioxide (SiO2)
Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)
Sandstone
Arenite (general term for sandstone)
Crinoid Stem Fossil
Class Crinoidea (Phylum Echinodermata), primarily Calcium Carbonate (CaCO3)
Chert (Flint)
Chert (SiO2)
Chert or Chalcedony
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (SiO2 predominantly)
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Peridot
Olivine ((Mg, Fe)2SiO4)