Quartz-veined Sedimentary Rock
Hydrothermally veined Clastic Sedimentary Rock (SiO2 veins in Matrix)
sedimentary
Category
Sedimentary (Volcanic)
Browse sedimentary (volcanic) specimens identified by the Rock Identifier community.
Chert (and associated Sedimentary rocks)
Microcrystalline Silica (SiO2)
sedimentary
Sandstone (Quartzose)
Arenite (Siliciclastic sedimentary rock)
sedimentary
Gold Sheen Obsidian
Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)
igneous
Obsidian
Obsidian (Volcanic glass), 70-75% SiO2
igneous
Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)
Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)
mineraloid / industrial byproduct
Ironstone Concretion / Limonite
Goethite and Limonite (FeO(OH)·nH2O)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock with secondary mineral infilling)
igneous
Agate (Polished Nodule)
Agate (Silicon Dioxide, SiO2)
mineral
Basalt with Magnetite
Crystalline Basalt (Primarily Plagioclase and Pyroxene) with Magnetite (Fe3O4)
igneous
Banded Agate (specifically Carnelian Agate)
Cryptocrystalline Quartz (SiO2)
mineral
Conglomerate
Conglomerate (a clastic sedimentary rock)
Sedimentary Rock
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
sedimentary
Sandstone (Quartzite-rich)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (lithic wacke/arenite)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (SiO2 based)
sedimentary
Agate (specifically, likely a geode slice or nodule)
Agate (a variety of Chalcedony, with chemical formula SiO2)
Mineral
Greenstone
Greenschist (commonly containing Chlorite, Actinolite, and Epidote)
metamorphic
Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Basalt with Iron Oxidation
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Crushed Rock (Basalt)
Basalt (Aphanitic Mafic Igneous Rock)
Igneous
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Sandstone
Arenite (Siliclastic Sedimentary Rock)
sedimentary
Sandstone
Sandstone (lithified arenite/wacke)
Sedimentary Rock
Vesicular Basalt (or Scoria)
Vesicular Basalt
igneous
Greenstone / Epidosite
Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)
metamorphic
Orca Agate
Chalcedony (SiO2) with various inclusions
mineral
Red Scoria (Lava Rock)
Scoria (Vesicular Basalt)
igneous
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Crazy Lace Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Diabase (also known as Dolerite)
Diabase
igneous
Basalt Pebble
Aphanitic Mafic Igneous Rock
igneous
Porphyritic Rhyolite
Porphyritic Rhyolite
igneous
Basalt River Rock
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Amethyst Geode
Silicon Dioxide (SiO2) - Amethyst variety of Quartz
mineral
Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
igneous
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Milky Quartz
Silicon Dioxide (SiO₂)
Mineral
Basalt with Iron Oxidation
Extrusive Mafic Igneous Rock (composed of Plagioclase and Pyroxene)
igneous
Blue Sapphire
Corundum (Al2O3 with trace Titanium and Iron)
mineral
Granite Cobble
Felsic Intrusive Igneous Rock
igneous