Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Category
Browse not a rock (synthetic material) specimens identified by the Rock Identifier community.
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Chert (Yellow/Brown Jasper)
Silicon Dioxide (SiO2)
Ferruginous Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
Quartzite
Quartzite (primarily SiO2)
Tumbled green-and-white stone, likely serpentine
Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile), commonly with magnetite and carbonate veins
Chert / Flint
Cryptocrystalline Quartz (Silicon Dioxide, SiO2)
Petrified Wood (Silicified Wood)
Silicified Wood / Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (mainly Quartz/Chalcedony, SiO2)
Sandstone (Ferruginous)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
Petrified Wood
Silicified Wood (SiO2)
Banded Chert (or Flint)
Microcrystalline Quartz (SiO2)
Mica Schist
Schist (Mica-rich Metamorphic Rock)
Coquina / Fossiliferous Limestone
Calcareous bioclastic sedimentary rock (CaCO3)
Olivine/Peridot
Magnesium Iron Silicate (Mg,Fe)2SiO4
Pumice
Pumice (Amorphous volcanic glass)
Serpentinite (often containing Jadeite/Nephrite)
Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4
Chert / Chalcedony
Silicon Dioxide (SiO2)
Chert / Jasper / Agate (Chalcedony Group)
Microcrystalline Quartz (SiO2)
Limonite (Yellow Ochre)
FeO(OH)·nH2O (Hydrous iron(III) oxide-hydroxide mixture)
Small rounded pebble, likely quartz-rich stone
Indeterminate from photograph; possibly microcrystalline quartz (SiO₂) or a weathered silicate pebble
Vesicular Basalt
Basalt (Mafic volcanic rock)
Tumbled quartz-rich pebble
Microcrystalline quartz (SiO₂), possibly weathered chert or chalcedony
Dark basalt or fine-grained mafic rock
Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine or iron-titanium oxides
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Chert (Light Variety)
Sedimentary cryptocrystalline quartz (SiO2)
Chert (also known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossilized Brachiopod
Brachiopoda (e.g., Atrypa or Rhynchonellida)
Red Sandstone
Clastic Sedimentary Rock (typically contains Quartz and Iron Oxide)
Sandstone (Quartzose)
Arenite (Formula: SiO2 primary, with various cements)
Muscovite Mica
Muscovite KAl2(AlSi3O10)(OH)2
Orbicular jasper (likely ocean jasper)
Silica-rich microcrystalline quartz/chalcedony with iron-oxide and other mineral inclusions; commonly classified as orbicular jasper
Mica Schist
Mica Schist (primarily Muscovite or Biotite)
Chert / Jasper
Silicon Dioxide (SiO2)
Hag Stone
Perforated Sedimentary Rock (typically Limestone or Sandstone)
Schist
Mica Schist (primarily Muscovite [KAl2(AlSi3O10)(OH)2] or Biotite)
Turquoise cabochon
Turquoise; hydrated copper–aluminum phosphate, approximately CuAl6(PO4)4(OH)8·4H2O (composition varies)
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
Quartzite River Rock
Quartzite (primarily SiO2)
Ventifact
Eolian Ventifact (often composed of basalt, chert, or quartzite)
Weathered sandstone or arkosic sandstone
Clastic sandstone, likely quartz–feldspar-rich (arkose)
Vesicular basalt (probable)
Basalt, mainly plagioclase feldspar and pyroxene, with possible olivine and iron oxides
Fulonite (Fulgurite-like)
Fulgurite (SiO2 fused silica/lechatelierite)