Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
Category
Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite or Iron Oxide inclusions
Quartz (likely a clear or rock crystal variety)
Quartz (SiO2 - Silicon Dioxide)
Orange Calcite
Calcium Carbonate (CaCO3)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Red Jasper
Silicon dioxide (SiO2) with hematite impurities
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Jasper with Iron Staining
Silicon Dioxide (SiO2) with impurities
Graywacke (River Cobble)
Graywacke (Lithic Sandstone)
Coquina
Coquina (a type of limestone)
Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert Pebble (with Quartz Vein)
Chert (Cryptocrystalline Silica - SiO2)
Chert (specifically a variety like Flint or River Jasper with Iron Oxidation)
Microcrystalline Quartz (SiO2)
Quartz (likely Milky Quartz)
Quartz (SiO₂ - Silicon Dioxide)
Granite with Orthoclase and Hematite Staining
Phaneritic Felsic Igneous Rock (primarily SiO2 with KAlSi3O8)
Quartzite
Quartzite (primarily SiO₂)
Malachite
Malachite (Cu2CO3(OH)2)
Chert (specifically Jasper or Brown Chert node)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
Carnelian (a variety of Chalcedony)
SiO2 (Silicon Dioxide) with Iron Oxide impurities
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Sandstone (with Limonite staining)
Arenite (FeOx-rich)
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with inclusions of crocidolite or dumortierite
Calcite
Calcite (CaCO₃)
Green Aventurine (Green Quartzite)
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
Sandstone (Ferruginous)
Arenite (with Iron Oxide cement)
Sandstone
Arenite (composed primarily of SiO2)
Chalcedony (Banded/Mottled Variety)
Chalcedony (a cryptocrystalline variety of Quartz, SiO2)
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Basalt
Mafic volcanic rock (various silicate minerals including Pyroxene and Plagioclase)
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Jasper (Iron-rich)
Silicon Dioxide (SiO2) with Fe2O3 (Hematite) impurities
Granite
Granite (Felsic intrusive igneous rock)
Sandstone (Yellow/Tan)
Clastic sedimentary rock (primarily SiO2 with iron oxide staining)
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (Formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite)
Tufa
Calcareous Tufa (CaCO3)
Jasper Conglomerate (specifically Puddingstone)
Jasper Conglomerate (Siliceous sedimentary rock)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese