Petrified Wood
Silicified Wood (SiO2)
sedimentary
Category
Organic Materia (Not A Rock Or Mineral)
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Chert (potentially Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
River Pebble (Granite/Gneiss)
Granitic Pebble / Quartz-Feldspar Aggregate
igneous
Banded Agate (Dyed)
SiO2 (Silicon Dioxide / Microcrystalline Quartz)
mineral
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
mineral
Petrified Wood
Silicified Wood (Permineralized organic tissue)
fossil
Red Sandstone
Sandstone (principally Quartz with Iron Oxide coating)
sedimentary
Chert (Flint variety)
Microcrystalline context of Quartz (SiO2)
sedimentary
Black Onyx
Cryptocrystalline Quartz (SiO2 with organic/iron impurities)
mineral
Ferruginous Sandstone Concretion (Ironstone Phosphorite)
Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)
sedimentary
Honey calcite (likely rough cleavage fragment)
Calcite, calcium carbonate (CaCO₃)
mineral
Petrified Wood
Silicified Wood (SiO2)
fossil
Gabbro or Diorite with Quartz/Epidote Vein
Intrusive Igneous Rock (Plutonic)
igneous
Painted Rock / Geode Specimen
Silicon Dioxide with artificial pigment coating
mineral
Lapis Lazuli
(Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2 (Complex silicate rock)
metamorphic
Ironstone Concretion
Siderite or Goethite Concretion
sedimentary
Basalt (Vesicular or Porphyritic River Pebble)
Mafic Volcanic Rock (Aphanitic to Porphyritic Basalt)
igneous
Sandstone
Sandstone (composed predominantly of Quartz, SiO2)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
sedimentary
Granite
Intrusive Igneous Rock
igneous
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
mineral
Petrified Wood
Silicified Wood (primarily SiO₂)
sedimentary
Ironstone Concretion (Limonite/Goethite)
Iron oxide concretion (contains FeO(OH)·nH2O)
sedimentary
Chrysocolla on Matrix
Hydrated copper silicates ((Cu,Al)2H2Si2O5(OH)4·nH2O)
mineral
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2) within a geode
mineral
Chert (Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Quartz (Druzy)
Silicon Dioxide (SiO2)
mineral
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Porphyritic Basalt or Porphyritic Andesite
Porphyritic Extrusive Igneous Rock
igneous
Shale with Quartz Veins
Fissile Sedimentary Rock (SiO2)
sedimentary
Wishing Stone (Basalt/Metabasalt with Quartz-Feldspar Vein)
Veined Metabasalt / Veined Greywacke
metamorphic
Vesicular Basalt / Scoria pebble
Extrusive igneous rock with amygdaloidal infilling
igneous
Petrified Wood
Silicified wood (primarily SiO2)
fossil
Granite
Intrusive Igneous Rock
igneous
Banded Slate or Siltstone with Quartz/Calcite Veins
Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)
metamorphic
Pearl
Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Mixed Mineral Assortment (Pyrite, Kyanite, Agate, Jasper)
FeS2 (Pyrite), Al2SiO5 (Kyanite), SiO2 (Agate/Jasper)
mineral