Sandstone (likely Arkosic or Lithic)
Clastic Sedimentary Rock (SiO2 with accessory minerals)
Category
Browse anthropogenic specimen (man made) specimens identified by the Rock Identifier community.
Sandstone (likely Arkosic or Lithic)
Clastic Sedimentary Rock (SiO2 with accessory minerals)
River Stone (likely Quartzite or Chert)
Recrystallized Silicon Dioxide (SiO2)
Quartz (Milky or Clear variety)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartz (Milky or Cloudy Quartz)
Quartz (Silicon Dioxide, SiO2)
Jasper with Quartz inclusions
Silicon Dioxide (SiO2) with impurities
Ruby in Zoisite (Anyolite)
Anyolite (Combination of Corundum and Zoisite)
Agate
Silicon Dioxide (SiO2) - Chalcedony variety
Chert (Iron-stained)
Chert (SiO2 - Silicon Dioxide)
Jasper (Multi-colored) / Sea Glass Slag
Silicon Dioxide (SiO2) with impurities of Iron Oxide
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Banded Onyx (Calcite Marble)
Calcite (CaCO3) - Trap-rock or Cave Onyx
Basalt with Hematite staining
Extrusive mafic igneous rock with Fe2O3
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Blue Dyed Agate
Silicon Dioxide (SiO2)
Sandstone (Weathered Cobble)
Clastic sedimentary rock (primarily SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace impurities of Ti, Mn, or Fe
Basalt (Water-worn pebble)
Mafic Igneous Rock (primarily Plagioclase feldspar and Pyroxene)
Sandstone (Pebble)
Clastic sedimentary rock (SiO2 primary)
Limonite (Ironstone Concretion)
Limonite (Hydrated iron(III) oxide-hydroxide, mixtures of FeO(OH)·nH2O)
Granitic Pegmatite (River Rock specimen)
Granite / Pegmatite (composed of SiO2, KAlSi3O8, and NaAlSi3O8)
Fuchsite
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
Amber
Succinite (fossilized tree resin), C10H16O
Fossiliferous Limestone
CaCO3 (principally Calcite or Aragonite)
Chert
Microcrystalline Quartz (SiO2)
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
Granite Pebble (Weathered)
Phaneritic Felsic Igneous Rock
Greenstone / Greenstone Pebble
Greenschist (metamorphosed basalt or gabbro)
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
Basalt (River-worn Specimen)
Extrusive Mafic Igneous Rock
Basalt
Basalt (composition of plagioclase, pyroxene, and olivine)
Basalt with Vesicular Texture
Basalt (SiO2 range 45-52%)
Granite (Weathered)
Phaneritic Felsic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Vuggy Quartz on Matrix
Silicon Dioxide (SiO2)
Obsidian with Spherulitic Devitrification (Snowflake Obsidian/Mahogany related)
Volcanic Glass (70% or more SiO2)
Agate (Water-Worn Pebble)
Silicon Dioxide (SiO2) - Chalcedony
Basalt
Basalt (dominated by Plagioclase Feldspar and Pyroxene)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
White Quartz (Milky Quartz Mushroom)
Silicon Dioxide (SiO2)
Magnetite (potentially Hematite-rich)
Magnetite (Fe3O4)
Chalcedony with inclusions (Agate/Quartz)
Silicon Dioxide (SiO2)