Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Category
Mineral (Processed Alloy)
Browse mineral (processed alloy) specimens identified by the Rock Identifier community.
Yellow Jasper
Silicon Dioxide (SiO2) with Iron inclusions
sedimentary
Iron-rich breccia (likely hematite–goethite breccia)
Hematite (Fe₂O₃) and goethite (FeO(OH)) in a silicified or iron-cemented breccia
sedimentary
Serpentinite
Serpentinite (complex silicate minerals including Mg3Si2O5(OH)4)
metamorphic
Ferruginous Sandstone (Ironstone)
Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)
sedimentary
Petrified Wood (Silicified Wood)
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
sedimentary
Porphyry (Porphyritic Basalt / Andesite)
Porphyritic Igneous Rock
igneous
Granite Pebble
Granitoid (Felsic Plutonic Rock)
igneous
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Serpentinite
Serpentinite (composed primarily of minerals in the Serpentine group: Chrysotile, Lizardite, and Antigorite)
metamorphic
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
mineral-based composite
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Granite
Intrusive igneous felsic rock
igneous
Serpentine
Serpentine group (e.g., Antigorite, Chrysotile, Lizardite) - (Mg,Fe)3Si2O5(OH)4
metamorphic
Red Jasper or Ironstone concretion
SiO2 or Fe2O3
sedimentary or mineral
Amethyst (Rough Quartz)
Silicon Dioxide (SiO2) with iron impurities
mineral
Petrified Wood (Jet or Coalified Wood appearance)
Silicified wood (principally SiO2) or Carbonized Wood
sedimentary
Limonite after Pyrite (Prophecy Stone)
Limonite (FeO(OH)·nH2O) replacing Pyrite (FeS2)
Mineral pseudomorph
Unakite
Epidotized Granite
Igneous rock
Limonite-stained Granite
Felsic Plutonic Rock with Hydrated Iron Oxides
igneous
Red Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Cubic Zirconia (Simulated Diamond)
Zirconium Dioxide (ZrO2)
mineral (synthetic)
Quartz Vein on Matrix
Silicon Dioxide (SiO2)
mineral
Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)
Diorite (Igneous rock, intrusive, intermediate composition)
Igneous Rock
Yellow Calcite (Banded)
Calcium Carbonate (CaCO3)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
mineral
Quartz Druzy on Matrix (likely Agate or Jasper)
Silicon Dioxide (SiO2) with various mineral inclusions
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Precious Opal
Hydrated amorphous silica (SiO2·nH2O)
mineral
Orbicular Jasper (Ocean Jasper)
Silicon Dioxide (SiO2) with iron and magnesium inclusions
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Serpentinite
Serpentinite (composed largely of Serpentine minerals such as Lizardite, Antigorite, and Chrysotile: Mg3Si2O5(OH)4)
metamorphic
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
fossil
Gneiss
Gneiss
metamorphic
Tiger's Eye
Tiger's Eye (a variety of Chalcedony, which is a microcrystalline quartz with fibrous inclusions of oxidized crocidolite)
Mineral
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
metamorphic
River Stone (Sedimentary Sandstone/Quartzite)
Arenite/Quartzite transition specimen
sedimentary
Tiger's Eye (Polished Point/Tower)
SiO2 (Silicon Dioxide) with included crocidolite fibers
Mineral (Metamorphic pseudomorph)