Quartz-rich pegmatite or quartz vein rock
Mostly quartz (SiO₂), with probable feldspar and iron-oxide staining
igneous
Category
Synthetic Material (Not A Rock Or Mineral)
Browse synthetic material (not a rock or mineral) specimens identified by the Rock Identifier community.
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Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Diorite
Intermediate plutonic igneous rock
Igneous
Biotite-bearing gneiss or schist
Quartz–feldspar–biotite metamorphic rock
metamorphic
Granite (specifically Rapakivi Granite)
Phaneritic Felsic Igneous Rock (Granite)
igneous
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Fossiliferous Siltstone
Clastic Sedimentary Rock with Fossil Inclusions
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Petrified Wood (Silicified Wood)
Silicified Wood / Silicon Dioxide (SiO2)
metamorphic
Vesicular basalt (weathered lava rock)
Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine (mafic volcanic rock)
igneous
Granite Pebble
Felsic Igneous Rock (Granitic composition)
igneous
Peridotite (Pyroxenite/Serpentinized Dunite)
Ultramafic Rock (consisting primarily of Olivine and Pyroxene)
igneous
Gray Granite
Phaneritic plutonic rock (Granite)
igneous
Granite
Intrusive Phaneritic Felsic Igneous Rock
igneous
Peridotite
Peridotite (primarily Olivine and Pyroxene)
igneous
Weathered iron-rich rock, possibly limonite-bearing sandstone or laterite
Limonite/goethite-rich ferruginous rock; exact identification requires testing
sedimentary
Pebble / Gravel Fragment
Clastic Rock Fragment
sedimentary
Bornite (“peacock ore”), likely weathered copper sulfide
Bornite, Cu₅FeS₄; possibly chalcopyrite, CuFeS₂, with iridescent tarnish
mineral
Tumbled blue quartzite or blue chalcedony (uncertain)
Quartz-rich rock; predominantly silicon dioxide (SiO₂)
metamorphic
Basalt
Mafic Igneous Rock (Basalt)
igneous
Rhyolitic jasper / brecciated jasper
Silica-rich volcanic rock, chiefly microcrystalline quartz (SiO₂), with iron-oxide and clay/mineral impurities
igneous
Fulonite (Fulgurite-like)
Fulgurite (SiO2 fused silica/lechatelierite)
Metamorphic (Pseudo-igneous)
Conglomerate
Conglomerate
sedimentary
Quartz-bearing granite or granitic gneiss cobble
Granite; primarily quartz (SiO₂), feldspar, and mica/amphibole
igneous
Glacial Erratic (Graywacke/Sandstone)
Clastic Sedimentary Rock (Lithic Sandstone)
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Fossilized Wood (Petrified Wood)
Agatized wood (primarily SiO2)
fossil
Tumbled basalt (likely)
Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, often with minor olivine and iron oxides
igneous
Granite
Phaneritic Plutonic Felsic Rock (SiO2 > 69%)
igneous
Quartz with Mica Schist
Quartz-Mica Schist / Pegmatitic Quartz
metamorphic
Jasper
Silicon Dioxide (SiO2) microcrystalline quartz
sedimentary
Quartz (Milky Quartz)
Quartz (Silicon Dioxide, SiO2)
mineral
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
sedimentary or metamorphic
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Green-and-white quartz-rich rock, likely chrysoprase or serpentine-bearing stone
Uncertain; possible chrysoprase (microcrystalline quartz, SiO₂) or serpentinite (magnesium silicate minerals)
mineral
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Schist with Quartz/Mica
Mica Schist (primarily Muscovite and Quartz)
Metamorphic
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
sedimentary
Ironstone Matrix with Jasper / Chert
Ferruginous Chert / Limonitic Jasper (SiO2 with Fe-oxides)
sedimentary
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary