Queen Conch Shell (Biogenic Calcium Carbonate)
Aliger gigas (synonym Strombus gigas); Composition: Aragonite (CaCO3)
mineral
Category
Biogenic Material
Browse biogenic material specimens identified by the Rock Identifier community.
Learn about Biogenic Material in the encyclopedia
View all →
Pearl necklace
Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)
gemstone
Fossiliferous Limestone
Biogenic Sedimentary Rock (primarily CaCO3 with fossil fragments)
sedimentary
Limestone with Calcite Veining
Calcium Carbonate (CaCO3) - Biogenic/Chemical Sedimentary Rock
sedimentary
Tahitian Black Pearl
Biogenic Calcium Carbonate (Aragonite/Conchiolin Mixture), CaCO3
mineral
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Sedimentary Rock
Calcite
Calcite (CaCO3)
Mineral
Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Kidney Stone (Medical Specimen)
Calcium oxalate monohydrate (Whewellite) / CaC2O4·H2O
Mineral (Biogenic)
Sea Shell (Fighting Conch Fragment)
Calcium Carbonate (CaCO3) - Strombus alatus fragment
sedimentary (biogenic)
Calcite (likely a tumbled specimen)
Calcite (CaCO 3 )
Mineral
Cockle Shell (Fossil or Recent)
Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)
Sedimentary (Biogenic, a type of fossil)
Chert
Chert (microcrystalline quartz, SiO2)
sedimentary
Calcite
Calcite (CaCO₃)
Mineral
Rhinestone
Artificial Glass/Crystal
gemstone
Coral limestone / fossil coral
Biogenic calcium carbonate, chiefly aragonite or calcite (CaCO₃); likely fossilized colonial coral
fossil
Note: This is a Man-Made Object (Costume/Prop Patch)
Synthetic fiber and pigments (Cellulose/Plastic-based composite)
Non-geological
Petrified Wood
Silicified Wood
fossil
Petrified Wood
Fossilized plant material (Silicon dioxide - SiO2)
fossil
Petrified Wood
Silicified Wood (Permineralized wood)
fossil
Sandstone
Sedimentary Rock (Quartz arenite)
sedimentary
Petrified Wood
Fossilized wood / Silicified wood
Sedimentary / Fossil
Granite / Gneiss (Coarse-Grained Felsic Rock)
Granite (Quartz-Feldspar-Mica aggregate)
igneous
Amber Inlay Jewelry
Fossilized Resin (C10H16O)
Organic Gemstone (Biogenic)
Fossilized wood fragment
Petrified wood; commonly silicified fossil wood (SiO₂ replacing organic tissue)
fossil
Tektite (likely indochinite)
Natural silica-rich impact glass; predominantly amorphous SiO₂ with aluminum, iron, magnesium, calcium, and sodium
mineral
Fossilized Shark Tooth (Cretaceous to Neogene)
Elasmobranchii dental fossil (likely Squalicorax or similar species)
mineral (biogenic replacement)
Sandstone
Sandstone (SiO2-rich clastic sedimentary rock)
sedimentary
Gastropod shell fragment
Calcareous mollusk shell; primarily aragonite or calcite (CaCO₃)
fossil
Granite (Unakite / Feldspar-rich Granite)
Granite (composed of Potassium Feldspar, Quartz, and Biotite/Epidote)
igneous
Faceted Gemstone
Unknown transparent mineral, possibly Diamond (C), Cubic Zirconia (ZrO2), Quartz (SiO2), or Glass
gemstone
Coquina
Coquina (Bioclastic Limestone)
sedimentary
Quartzite
Quartzite (SiO2-rich metamorphic rock)
metamorphic
Sandstone
Arenite (primary component SiO2)
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Asphalt Concrete
Bituminous Concrete / Asphaltic Composite
not a natural rock (man-made composite)
Blue Sphalerite (likely dyed or treated Druzy Quartz/Agate)
Zinc Sulfide (ZnS) or Silicon Dioxide (SiO2) with trade-name enhancement
Mineral
Crushed Stone / Gravel
Aggregate (mixed lithology)
sedimentary
Tiger’s-eye bead bracelet
Chatoyant quartz, principally quartz (SiO₂) with pseudomorphic fibrous crocidolite/goethite inclusions
gemstone
Tektite (Indochinite)
Tektite (High-silica impact glass)
igneous
Chert Pebble
Microcrystalline silica (SiO2)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary