Chert (specifically Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Category
Mineraloid (Human Made Geological Specimen)
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Chert (Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Agate (specifically Carnelian Agate slice)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
mineral
Chert (Polished River Pebble)
Chert (SiO2)
sedimentary
Crushed Limestone
Calcium Carbonate (CaCO3)
Sedimentary
Obsidian
Obsidian (volcanic glass), primarily SiO2 (silicon dioxide)
igneous
Chert (variations include Flint/Jasper)
Cryptocrystalline Silicon Dioxide (SiO2)
sedimentary
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)
igneous
Quartz pebble (Quartztite fragment)
Silicon Dioxide (SiO2)
mineral
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Igneous
Pink Dyed Agate (Banded Chalcedony)
Silicon dioxide (SiO2) - variety Chalcedony
mineral
Banded Chert (River Stone)
Silicon Dioxide (SiO2)
sedimentary
Asphalt Concrete (Bituminous Pavement)
Aggregates in Bitumen Matrix
Technogenic / Anthropogenic Pavement Material
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (mostly SiO2)
igneous
Cullet Glass (Strawberry Glass)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Mineraloid (Synthetic/Man-made)
Obsidian
Volcanic Glass (SiO2 rich)
Igneous
Sandstone-based Concrete Fragment
Cementitious Composite with Sedimentary Aggregate
sedimentary (man-made/anthropogenic)
Concretion (Sandstone)
Carbonate-cemented Sandstone Concretion
sedimentary
Libyan Desert Glass
Tektite (high-silica impact glass), SiO2
mineral
Chert (often called Flint in this variation)
Silicon dioxide (SiO2) - Microcrystalline quartz
sedimentary
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
sedimentary
Rainbow Hematite (Titanium Coated)
Iron(III) oxide (Fe2O3) with Titanium/Metal Oxide coating
mineral
Obsidian
Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)
igneous
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
mineral
Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
Mineraloid / Industrial Byproduct
Mahogany Obsidian
Obsidian (SiO2 + Fe2O3)
igneous
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Concrete
Hydrated Portland Cement Aggregate Composite
Anthropogenic Sedimentary (Man-made)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Blue Slag Glass
Amorphous Silica (Industrial byproduct)
Antropogenic (Man-made glass byproduct)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2
igneous
Blue Goldstone
Goldstone (artificial glass)
Mineral (man-made glass, not natural)
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 with impurities)
igneous
Asphalt (Bituminous Concrete)
Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)
not a rock (anthropogenic material/technofossil)
Ocean Jasper Mushroom
Orbicular Jasper (Silicon Dioxide, SiO2 mixed with various impurities)
mineral
Libyan Desert Glass
Libyan Desert Glass (SiO2 with trace elements)
mineral (impactite)
Slag
Anthropogenic glassy silicate
Mineral-like byproduct
Carborundum (Silicon Carbide)
Silicon Carbide (SiC)
mineral (synthetic)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)
igneous