Chert (Limestone-hosted Pebble)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Organic (Mineraloid)
Browse organic (mineraloid) specimens identified by the Rock Identifier community.
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Chert (Brown variety / Common Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Red Jasper
Jasper (Silicon Dioxide with Iron inclusions - SiO2)
Sedimentary/Metamorphic
Anthracite Coal
Anthracite
metamorphic
Chert (variously identified as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Chert (Tan/Grey variety)
Silicon Dioxide (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint or Jasper locally)
Chert (Microcrystalline Quartz, Formula: SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)
Mineral/Fossil (Sedimentary context)
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Unknown Organic Object (likely a berry or fruit)
Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.
Organic Material (likely a fruit or berry)
Dyed Blue Agate (Dragon Vein Agate)
Silicon Dioxide (SiO2) with artificial cobalt/organic dyes
mineral
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
sedimentary
Pearl
Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)
mineral
Mookaite Jasper
Silicified Radiolarite (SiO2)
sedimentary
Moss Agate
Chalcedony (Silicon Dioxide with inclusions) - SiO2
mineral
Chert (Weathered)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Ironstone Concretion / Hematite Nodules
Ferruginous Sedimentary Rock (primarily Hematite Fe2O3 and Goethite FeO(OH))
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
sedimentary
Limestone with Quartz/Calcite Veins
Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
sedimentary
Jasper (specifically Yellow Jasper and Red Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Banded Chert (with Quartz Vein)
Microcrystalline Silica (SiO2)
sedimentary
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
metamorphic
Chert (Chert Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Massive Cryptocrystalline Quartz (Chert/Chalcedony Pebble)
Silicon Dioxide (SiO2)
sedimentary
Travertine (often colloquially called Tufa)
Chemical Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Chert (specifically Iron-stained River Cobble)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
metamorphic
Green Banded Chert (Agate/Jasper)
Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Graphite
Graphite (Native Carbon, C)
metamorphic
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Chert (Cherty Flint/Jasper variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary