Sandstone (Tumbled/River Pebble)
Arenite (composed primarily of SiO2)
sedimentary
Category
Mineral Like Byproduct (Often Mistaken For Igneous Rock Or Meteorite)
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Sandstone (Red Sandstone / River Stone)
Arenite (composed primarily of Quartz, SiO2, with Iron Oxide cementation)
sedimentary
Basalt (River Cobble)
Basalt (Mafic Extrusive Igneous Rock)
igneous
Septarian Nodule Segment (Turtle Stone)
Septarian Concretion (CaCO3 with Siderite or Calcite infill)
sedimentary
Chert / Flint Nodules in Limestone
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
sedimentary
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Rose Quartz
Silicon dioxide with traces of titanium, iron, or manganese (SiO2)
mineral
Serpentine (Serpentinite)
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
sedimentary
Sandstone
Arenite (SiO2 with various cementing agents)
sedimentary
Prasiolite and Quartz Crystal Cluster
Quartz (SiO2); Prasiolite is a variety of Quartz
mineral
Obsidian
Obsidian (Volcanic Glass)
igneous
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Rough Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
mineral
Andesite Porphyry
Porphyritic Andesite (Intermediate volcanic rock)
igneous
Moss Agate
Agate (Silicon Dioxide, SiO2) with dendritic inclusions
sedimentary
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
mineral
Septarian Nodule (Galt)
Calcareous concretion / Septarian concretion
sedimentary
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary
Almandine Garnet
Almandite (Fe3Al2(SiO4)3)
Mineral
Smoky Quartz and Feldspar Pegmatite
Granitic Pegmatite (chiefly SiO2 and KAlSi3O8)
igneous
Chert (Polished Gemstone / River Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chalcedony (variations like Agate or Jasper)
Chalcedony (SiO₂ - microcrystalline quartz)
Mineral
Basalt
Extrusive mafic igneous rock
igneous
Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Geode (Unopened)
Siliceous Septarian Concretion / Geode (SiO2)
sedimentary
Quartz Geode (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Dalmatian Stone
Dalmatian Jasper (a misnomer for an Aplite with Arfvedsonite spots)
igneous
Pebble or Cobble (likely composed of sandstone or conglomerate)
Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)
Sedimentary Rock (possibly a conglomerate or coarse-grained sandstone)
Unakite
Unakite (Metasomatized Granite)
metamorphic
Serpentine Schist with Quartz Vein
Serpentine Schist (a type of Metamorphic rock). The white band is likely Quartz (SiO2).
Metamorphic
Basalt with Desert Varnish
Mafic Volcanic Rock (Fe/Mg rich Silicate)
igneous
Sandstone
Arenite
sedimentary
Shale
Mudstone/Shale
sedimentary
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
sedimentary
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
mineral
Shale
Fissile mudstone (Shale)
sedimentary