Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2)
Category
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz (Riverstone / Cobble)
Silicon Dioxide (SiO2)
Amber
Succinite
River Cobble (Gneiss/Migmatite)
Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)
River Quartz Pitting/Cobble
Silicon Dioxide (SiO2)
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
Granite Pebble
Felsic Intrusive Igneous Rock (composed of Quartz, Feldspar, and Mica)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Chalcedony (Botryoidal Agate)
Silicon Dioxide (SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Carnelian (Orange Agate/Chalcedony)
Silicon Dioxide (SiO2) - variety of Chalcedony
Synthetic Sapphire and Ion-X Glass
Single-crystal Alumina (Al2O3) and Ion-strengthened Aluminosilicate Glass
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Specular Hematite
Hematite (Fe2O3)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Red Sandstone
Arenite (Ferruginous Sandstone)
Milky Quartz
Silicon Dioxide (SiO2)
Greenschist
Chlorite schist
Ferruginous Sandstone
Arenite with Iron-Oxide cement (Fe2O3 · nH2O)
Amber
Fossilized Tree Resin (C10H16O)
Botryoidal Quartz / Calcite Geode crust
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
Ferruginous Sandstone
Ferruginous Clastic Sedimentary Rock
Quartz
Silicon Dioxide (SiO2)
Green Aventurine
Silicon Dioxide (Quartz) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Quartz Crystal
Quartz (SiO₂)
Banded Agate
Cryptocrystalline Quartz (SiO2)
Green Calcite
Calcite (CaCO3)
Sandstone
Arenite (primarily SiO2)
Quartz Druzy on Matrix (likely Agate or Jasper)
Silicon Dioxide (SiO2) with various mineral inclusions
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Biotite Schist
Biotite Schist (predominantly K(Mg,Fe)3AlSi3O10(OH,F)2)
Diamond (in a jewelry setting)
Diamond (Carbon, C)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Water-worn Pebble)
Silicon Dioxide (SiO2)
Amethyst
Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities
Basalt
Mafic volcanic rock (primarily Plagioclase and Pyroxene)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (70–75% SiO2)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Sandstone (Pebble)
Arenite / Clastic Sedimentary Rock
Geode (Unopened)
Siliceous Geode (SiO2)