Sandstone Concretion
Sedimentary concretion
Category
Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.
Sandstone Concretion
Sedimentary concretion
Red Quartzite Cobble
Quartzite (primarily SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Quartzite
Quartzite (mainly SiO2)
Amethyst (Agate/Chalcedony variety)
Silicon Dioxide (SiO2) with iron impurities
Sandstone (Quartzose)
Arenite (primarily SiO2)
Basalt (Vesicular)
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 predominantly)
Basalt Pebble
Basalt (Mafic volcanic rock)
Banded Gneiss
Gneiss
Vesicular Basalt (Pumice-like)
Vesicular Basalt
Sandstone (Ferruginous)
Arenite with Iron Oxide (Limonite/Hematite) coating
Red Jasper or Chert
Jasper (SiO2, a variety of chalcedony with iron oxide impurities), Chert (SiO2)
Chert (specifically Jasper or Brown Chert node)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Basalt with Caliche
Extrusive Mafic Igneous Rock with Secondary Carbonate Crust
Milky Quartz
Silicon Dioxide (SiO2)
Crushed Limestone
Calcium Carbonate (CaCO3)
Sandstone (with Iron Siderite Concretion)
Arenite with Ironstone Concretion (FeCO3)
Calcite
Calcite (CaCO₃, Calcium Carbonate)
Sandstone (Quartzose)
Arenite (SiO2 based)
Chrysocolla in Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix
Quartz Geode
Silicon Dioxide (SiO2) within a geode
Chert
Chert (microcrystalline quartz, SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone (with garnet granules)
Clastic sedimentary rock (primarily SiO2 with Fe3Al2(SiO4)3 inclusions)
Orange Quartzite (Tumbled Beach Pebble)
Quartzite (primarily SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst (as a jewelry accent)
Amethyst (Silicon Dioxide SiO2 with Iron impurities)
Basalt River Pebble
Basalt (Mafic Extrusive Volcanic Rock)
Dalmatian Stone
Peralkaline Feldsphathic Igneous Rock
Chert (Nodular Chert)
Microcrystalline Silica (SiO2)
Sandstone (Quartz Arenite)
Sandstone (SiO2 with possible mineral cements)
Porphyritic Andesite
Intermediate Volcanic Rock - Andesite
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Quartzite (River Pebble)
Quartzite (composed primarily of Silica, SiO2)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Basalt
Mafic Volcanic Rock (Primarily Plagioclase feldspar and Pyroxene)
Basalt
Basalt
Chert (Quartz Variety)
Chert (Silicon Dioxide, SiO2)
Basalt
Basalt (Mafic Extrusive Igneous Rock)