Agate (specifically, likely a geode slice or nodule)
Agate (a variety of Chalcedony, with chemical formula SiO2)
Mineral
Category
Mineral (Specifically A Mineraloid)
Browse mineral (specifically a mineraloid) specimens identified by the Rock Identifier community.
Agate (specifically Carnelian Agate or Sardagate)
Silicon dioxide (SiO2) - variety of chalcedony
mineral
Banded Agate (specifically Sardonyx or Carnelian Agate)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Banded Agate (specifically Carnelian Agate / Sardonyx)
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)
igneous
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Mineral
Hematite
Hematite (Fe2O3)
mineral
Quartzite (specifically Milky Quartz variety)
Quartz (SiO2)
metamorphic
Pebble (river rock/beach pebble)
Pebble (clast size class)
Sedimentary Rock
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
sedimentary
Ring with an Orange Inlay
N/A (Man-made object)
Man-made Object (Ring)
Gneiss (specifically Banded Gneiss)
Gneiss
metamorphic
Strawberry Quartz
Quartz (SiO2) with inclusions of Goethite or Hematite
Mineral
Sandstone (specifically Arkose or Quartz Arenite)
Arenite (primarily SiO2 with possible Feldspar)
sedimentary
Jasper (specifically Picture Jasper or Landscape Jasper)
Silicon Dioxide (SiO2) - Opaque variety of Chalcedony/Quartz
sedimentary
Peridot (likely, based on color and appearance)
Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)
Mineral
Jasper (specifically Red Jasper or Iron-stained Chert)
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert (specifically Agate/Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Banded Agate (specifically Botryoidal/Orbicular Agate)
Silicon Dioxide (SiO2)
Mineral (variety of Chalcedony/Quartz)
Gneiss (specifically Pink Gneiss)
Gneiss (high-grade regional metamorphic rock)
metamorphic
Picture Jasper (specifically Biggs or Deschutes variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Blue Quartz (specifically Dumortierite Quartz)
Silicon Dioxide (SiO2) with inclusions of Dumortierite (Al7BO3(SiO4)3O3)
metamorphic
Jasper (specifically Fancy or Polychrome Jasper)
Silicon Dioxide (SiO2) - Chalcedony
Sedimentary
Smoky Quartz
Smoky Quartz (SiO2)
Mineral
Granite
Granite (felsic intrusive igneous rock)
igneous
Amethyst
Amethyst (SiO₂)
Mineral
Rutilated Quartz
SiO2 (Quartz) with TiO2 (Rutile inclusions)
Mineral
Yellow Aventurine
Quartzite with inclusions (SiO2)
metamorphic
Gneiss (specifically Micaceous Gneiss)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Jasper (specifically Fancy Jasper or Bloodstone variety)
Silicon Dioxide (SiO2) with impurities (Iron oxides/silicates)
sedimentary
Sandstone (specifically Cross-bedded Sandstone)
Arenite (composed primarily of SiO2)
sedimentary
Synthetic Resin (Artificial Specimen)
Polyurethane or Polyester Resin
mineraloid (man-made)
Chert (specifically Jasper/Carnelian variety)
Microcrystalline quartz (SiO2)
sedimentary
Snowflake Obsidian
Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions
igneous
Gneiss (specifically Amphibolite Gneiss)
Gneiss
metamorphic
Obsidian (specifically Silver Sheen Obsidian)
Volcanic Glass (approx. 70–75% SiO2 plus MgO, Fe3O4)
igneous
Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
Mineraloid / Industrial Byproduct
Green Aventurine
Aventurine (a variety of Quartz, SiO2)
Mineral
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Sedimentary
Chevron Amethyst
Quartz (SiO2) with patterned Amethyst and White Quartz/Milky Quartz
mineral
Orange Calcite
Calcite (CaCO3)
Mineral
Chert (specifically Jasper or Flint variant)
Cryptocrystalline Quartz (SiO2)
sedimentary