Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide / Chalcedony)
metamorphic
Category
Organic Mineraloid
Browse organic mineraloid specimens identified by the Rock Identifier community.
Learn about Organic Mineraloid in the encyclopedia
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Septarian Nodule (Dragon Stone)
Septarian Nodule (Calcium Carbonate/Aragonite/Calcite Concretion)
sedimentary
Chert (specifically a stream-worn Chert Nodule)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified wood (SiO2)
sedimentary
Fossilized Bone Fragment
Vertebrate Fossil Material (Apatite/Calcium Phosphate)
fossil
Green Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
fossil
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petoskey Stone
Hexagonaria percarinata (Fossilized Coral)
sedimentary
Black Marble with Quartz Veining
Metamorphosed Limestone (Recrystallized CaCO3)
metamorphic
Amber (Copal)
Organic gemstone, fossilized tree resin (often immature amber or copal)
Mineral
Hardpan Nodule / Ferruginous Sandstone
Ferruginous Sandstone (Fe-cemented sediment)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Polished petrified wood
Silicified wood, primarily microcrystalline quartz (SiO₂) replacing organic tissue
fossil
Amber
(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.
Mineral
Petrified Wood
Silicified wood (Quartz / Chalcedonized wood, SiO2)
sedimentary
Anthracite Coal
Anthracite (Metamorphic/High-grade Sedimentary Coal)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Graphite
Graphite (Carbon, C)
Mineral
Pink Opal / Peruvian Opal
Hydrated amorphous silicon dioxide (SiO2·nH2O)
Mineral
Petrified Wood
Silicified wood (primarily quartz, SiO2)
fossil
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
sedimentary
Petrified Wood
Silicified wood (primarily SiO2)
sedimentary
Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Red Jasper (beads)
SiO₂ (Silicon Dioxide)
Mineral, variety of chalcedony (microcrystalline quartz)
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
mineraloid / anthropogenic (man-made origin)
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various additives
Man-made material (Anthropogenic 'mineraloid')
Chert / Flint
Chert (varieties include Flint)
Sedimentary
Fordite
Anthropogenic paint-rock
mineraloid (human-made geological specimen)
Sea Glass (specifically Frosted White)
Amorphous Silica (substance: Sodium-calcium silicate glass)
Mineraloid (Anthropogenic/Man-made rock)
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Mineral/Mineraloid within a rock matrix
Shale
Shale
sedimentary
Fossilized wood fragment
Petrified wood; commonly silicified fossil wood (SiO₂ replacing organic tissue)
fossil
Petrified Wood
Silicified wood (Quartz / Chalcedony replacement)
fossil
Chert / Flint
Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂
Mineral
Pyrite
Pyrite (FeS2)
Mineral