Chalcedony
Chalcedony (SiO2)
mineral
Category
Sedimentary And Igneous
Browse sedimentary and igneous specimens identified by the Rock Identifier community.
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Magnetic Sand Grain / Magnetite Pellet
Magnetite (Fe3O4)
mineral
Clear Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
mineral
Garnet (specifically Almandine)
Almandine - Fe3Al2(SiO4)3
metamorphic
Quartz (Granular)
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Likely weathered sandstone or iron-stained sedimentary rock
Quartz-rich sandstone; exact identification is limited by the blurred photograph
sedimentary
Yellow chalcedony or quartz fragment
Microcrystalline quartz, SiO₂ (tentative; possibly iron-stained chalcedony)
mineral
Purple Dyed Dalmatian Stone
Dyed Peralkaline Trachyte
igneous
Dalmation Stone
Peralkaline Rock (Microcline Quartz mixture with Arfvedsonite)
igneous
Dalmation Stone
Peralkaline Rock (SiO2 with Arfvedsonite)
igneous
Milky Quartz in Matrix
Silicon Dioxide (SiO2)
mineral
Dalmatian Stone
Peralkaline Feldsphathic Igneous Rock
igneous
Fossilized shell fragment
Indeterminate fossil mollusk; likely a silicified or mineral-replaced bivalve/gastropod fragment
fossil
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Rounded gray sandstone or siltstone cobble
Lithified quartz–feldspar–clay sediment; exact petrographic identification requires testing
sedimentary
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
mineral
Dalmation Stone (Dalmation Jasper)
Peralkaline rock (primarily Feldspar and Quartz with Arfvedsonite spots)
igneous
Fossilized marine shell fragment
Likely a bivalve or gastropod shell preserved as calcite (CaCO₃)
fossil
Orbicular rhyolite (likely)
Silica-rich volcanic rock, chiefly quartz and feldspar with orbicular aggregates of feldspar, quartz, and mafic minerals
igneous
Weathered limestone or calcareous sandstone
Calcitic carbonate rock, likely limestone (CaCO₃), possibly slightly dolomitic
sedimentary
Silicified oyster fossil
Fossil oyster shell, commonly Ostrea or Crassostrea, replaced or encrusted by chalcedony/quartz
fossil
Dalmatian Jasper
Peralkalic Quartz-Feldspar Porphyry
igneous
Dalmatian Stone
Peralkaline rhyolite
igneous
Granite
Felsic intrusive igneous rock
igneous
Dalmatian Stone (often misnamed Dalmatian Jasper)
Aplite (with hornblende/arfvedsonite inclusions)
igneous
Quartz pebble
Silicon dioxide (SiO2)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
gemstone
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Quartz
Silicon dioxide (SiO2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Optical Calcite
Calcium Carbonate (CaCO3)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Calcite on Matrix
Calcium Carbonate (CaCO3)
mineral
Mixed Mineral Collection
Multi-mineral Assemblage (Quartz, Jasper, Obsidian, Pyrite, etc.)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Crystal
Silicon Dioxide (SiO2)
mineral