Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
mineral
Category
Mineral (Silicate Replaced Organic Material)
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
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Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Greenschist (Chlorite Schist)
Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)
metamorphic
Greenstone
Greenschist (containing chlorite, epidote, and actinolite)
metamorphic
Basalt (Greenstone)
Basalt with chlorite/epidote (often referred to as Greenstone)
igneous
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and mineral impurities
sedimentary
Fossilized Sand Tiger Shark Tooth
Carcharias sp. (likely Carcharias taurus or Striatolamia)
fossil
Chert (Nodular)
Microcrystalline Quartz (SiO2)
sedimentary
Orthoceras Fossil
Orthoceras regulare (Extinct Cephalopod)
fossil
Fossilized Shark Tooth
Fossil Chondrichthyes (various genera such as Carcharias or Odontaspis)
sedimentary
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Organic Gemstone/Biomineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with Iron inclusions)
Mineral
Fossilized Coral (Petoskey Stone / Chain Coral)
Scleractinia (Order) / Halysites (Genus for Chain Coral types)
sedimentary
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Yellow Jasper
Silicon Dioxide (SiO2)
sedimentary (microcrystalline silicate)
Tiger's Eye
Silicon dioxide (SiO2) with crocidolite inclusions
Mineral
Tiger's Eye (Mineral Collection)
Tiger's Eye (SiO2 with crocidolite inclusions)
mineral
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Fire Opal (in Matrix)
Hydrated Silica (SiO2·nH2O)
mineral
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Tiger's Eye
Tiger's Eye (a variety of Chalcedony, which is a microcrystalline quartz with fibrous inclusions of oxidized crocidolite)
Mineral
Chert with Calcite Veins
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) intrusions
sedimentary
Banded Chert
Cryptocrystalline Quartz (SiO2)
sedimentary
Olivine
Magnesium Iron Silicate ((Mg, Fe)₂SiO₄)
mineral
Limonite (Iron Stone)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
mineral
Chert (and/or Flint)
Silicon Dioxide (SiO2)
sedimentary
Porphyritic Andesite
Andesite (with white Plagioclase phenocrysts)
igneous
Amber (Copal)
Succinite (fossilized resin)
mineral
River Cobble (likely Basalt or Greenstone)
Mafic Igneous Rock (with possible chloritic alteration)
igneous
Limonite Pseudomorph after Pyrite
Limonite (FeO(OH)·nH2O) replacing Pyrite (FeS2)
mineral
Basalt with Epidote/Chlorite
Amygdaloidal Basalt (SiO2 with (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)))
igneous
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
sedimentary
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Green Jasper
Silicon Dioxide (SiO2) with iron silicate inclusions
sedimentary
Amber
Succinite
Organic Mineraloid
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe/Chlorite)
mineral
Siltstone River Rock
Siltstone (composed of silt-sized particles, silicate minerals)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 inclusions)
sedimentary
Amber
Succinite (fossilized tree resin)
mineral
Amber
Succinate (Succinite for Baltic varieties)
mineraloid
Amber
Succinite (Resin)
mineral