Fossil shark tooth
Likely fossilized shark tooth, possibly Carcharhinus or Otodus species
fossil
Category
Sedimentary Or Metamorphic
Browse sedimentary or metamorphic specimens identified by the Rock Identifier community.
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Polished malachite
Malachite, Cu₂CO₃(OH)₂
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Jasper (Red Jasper)
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Likely quartz fragment
Quartz (silicon dioxide, SiO₂), possibly milky quartz or quartz-rich rock
mineral
Pearl
Pearl; primarily aragonite (CaCO₃) in nacre
gemstone
Pyrite-bearing rock (likely pyrite-rich quartz or schist)
Pyrite, FeS₂, intergrown with quartz and/or mica-rich matrix
mineral
Pearl-bearing oyster shell
Nacreous shell, primarily aragonite (CaCO₃), with natural pearls (calcium-carbonate nacre)
fossil
Red Jasper
SiO2 (Silicon Dioxide with Iron inclusions)
sedimentary
Yellow-green serpentine (likely)
Serpentine-group phyllosilicate, commonly lizardite or antigorite; approximate formula Mg₃Si₂O₅(OH)₄
mineral
Pearl
Nacre (aragonite, CaCO₃, in an organic conchiolin matrix)
gemstone
Desert rose
Gypsum (selenite) rosette, CaSO₄·2H₂O
mineral
Mixed rock and mineral collection
Multiple specimens; visible pieces may include quartz, calcite, agate/chalcedony, jasper, and dyed or coated materials
mineral
Pyrite on Quartz
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
mineral
Tumbled quartz-rich pebble
Microcrystalline quartz (SiO₂), possibly milky quartz or chalcedony
mineral
Pyrite on Quartz matrix
Iron Disulfide (FeS2) on Silicon Dioxide (SiO2)
mineral
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Limonite Pseudomorph after Pyrite
Goethite/Limonite FeO(OH)·nH2O replacing Pyrite FeS2
mineral
Jasper
Silicon dioxide (SiO2)
sedimentary
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Brecciated Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
White Quartz Star-cut crystal
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Likely weathered sandstone or metasandstone
Quartz-rich sandstone (possibly weakly metamorphosed metasandstone)
sedimentary
Raw quartz fragment
Quartz (SiO₂), likely milky or included quartz
mineral
Small pale mineral fragment, likely quartz or calcite
Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing
mineral
Weathered iron-stained quartzite or chert nodule
Siliceous rock composed chiefly of microcrystalline quartz (SiO₂), with iron-oxide staining and possible clay/minor carbonate minerals
metamorphic
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Quartz-rich rock, possibly quartzite
Quartzite (dominantly quartz, SiO₂); identification is provisional from the photo
metamorphic
Banded calcite (likely cave deposit or vein fragment)
Calcite, CaCO₃
mineral
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Tumbled amethyst
Amethyst, purple variety of quartz (SiO₂)
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Pearl necklace
Pearl—biogenic calcium carbonate, primarily aragonite (CaCO₃)
gemstone
Likely anthracite coal fragments
Anthracite; predominantly carbon (C), with minor mineral ash
sedimentary
Feldspar-rich Quartzite
Metamorphic Quartz-Feldspar Aggregate (SiO2 + KAlSi3O8)
metamorphic
Sandstone or Quartzite
Sandstone or Quartzite (SiO2 primarily)
sedimentary or metamorphic
Carnelian
Carnelian (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is a cryptocrystalline quartz)
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sedimentary or Metamorphic
Shale or Slate
Shale (Sedimentary) or Slate (Metamorphic)
sedimentary or metamorphic