Fossilized shell fragment, likely bivalve
Bivalvia indet.; commonly preserved as calcite (CaCO₃) shell material
Category
Browse igneous or metamorphic specimens identified by the Rock Identifier community.
Fossilized shell fragment, likely bivalve
Bivalvia indet.; commonly preserved as calcite (CaCO₃) shell material
Fossilized marine shell fragment
Likely a bivalve or gastropod shell preserved as calcite (CaCO₃)
Likely quartz-rich stone (possibly milky quartz or quartzite)
Quartz, silicon dioxide (SiO₂), or quartzite if interlocking grains are present
Fossiliferous limestone fragment
Calcitic limestone; mainly calcium carbonate (CaCO₃), possibly with shell or coral debris
Fossilized bivalve shell or shell-rich limestone
Likely an indeterminate fossil mollusk; calcite/aragonite (CaCO₃), possibly preserved in limestone
Granite with Epidote
Granite, containing quartz, feldspar, and epidote
Biotite Mica Schist
Metamorphic Rock containing Biotite K(Mg,Fe)3AlSi3O10(OH)2
Eclipse Stone (Kabamba Jasper)
Rhyolite with Aegirine (NaFe3+Si2O6)
Conical fossil shell or shell fragment
Likely a gastropod shell fragment; exact taxon indeterminate from the image
Likely weathered fossil shell or fossiliferous limestone
Indeterminate molluscan fossil, possibly a bivalve or brachiopod preserved in carbonate rock
Milky Quartz
Silicon Dioxide (SiO2)
Petrified wood
Silicified wood; commonly quartz/chalcedony (SiO₂) replacing organic tissue
Fossil shell or shell fragment
Likely a calcareous bivalve or gastropod fragment; precise identification requires locality and microscopy
Feldspar (Plagioclase / Potassium Feldspar)
Feldspar Group (KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8)
Weathered fossiliferous limestone, likely coral or shell fragment
Calcite (CaCO₃), biogenic limestone; exact fossil taxon indeterminate from the image
Fossil shell fragment, likely bivalve or gastropod
Fossilized calcium-carbonate shell; likely aragonite/calcite replaced by calcite
Greenstone / Serpentinite
Serpentine-group / Altered Mafic Rock
Fossil shell fragment, likely bivalve or brachiopod
Indeterminate fossilized mollusk/brachiopod; commonly calcite (CaCO₃)
Weathered quartz-bearing rock, likely granite or granitic gneiss
Feldspar–quartz–mica aggregate; probable granite (compositionally, quartz + feldspar + biotite/muscovite)
Cloudy Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Milky and Smoky variety)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
Fossil-bearing fine-grained sedimentary rock
Likely fossiliferous mudstone or shale; visible feature may be a plant fragment, trace fossil, or mineral vein
Biotite Schist
Biotite Gneissic Schist (K(Mg,Fe)3AlSi3O10(OH)2)
Pegmatite
Pegmatitic Granite containing Quartz, Feldspar, and Schorl
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Milky quartz
Quartz, silicon dioxide (SiO₂)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Raw and Water-worn)
Silicon Dioxide (SiO2)
Milky Quartz with inclusions
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Hypersthene (or Enstatite/Ferrosilite)
Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)
Likely quartz-bearing rock or mineral fragment
Indeterminate; possibly quartz (SiO₂) with iron-oxide staining and darker matrix
Clear Quartz
Silicon dioxide (SiO2)
Milky Quartz
Crystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)