Granite
Granite (phaneritic intrusive igneous rock consisting of quartz, feldspar, and mica)
Category
Browse mineral (man made glass) specimens identified by the Rock Identifier community.
Granite
Granite (phaneritic intrusive igneous rock consisting of quartz, feldspar, and mica)
Red Sandstone
Arenite (Fe2O3 enriched)
Chert (Flint variety)
Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2
Polished blue stone, likely sodalite or dyed agate
Sodalite: Na₈(Al₆Si₆O₂₄)Cl₂; exact identification requires testing
Chert (often called Flint or Jasper if reddish)
Microcrystalline Quartz (SiO2)
Granodiorite
Intrusive Igneous Rock
Blue Chalcedony
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Diamond (Cluster Ring)
Carbon (C)
Flower Agate
Chalcedony (SiO2) with inclusions
Onyx (Black) and Mother of Pearl Inlay
Silicon Dioxide (SiO2) for Onyx; Aragonite (CaCO3) for Mother of Pearl
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Titanium Coated Aura Quartz (Apple Aura Quartz)
Silicon Dioxide (SiO2) with Metallic Vapor Deposition Coating
Gemstone bead necklace (likely citrine or yellow quartz)
Quartz, SiO₂; precise identification is uncertain because the beads are blurred and metal settings obscure them
Sandstone
Arenite (composed primarily of SiO2)
Sandstone
Sedimentary Clastic Rock (Quartzose Sandstone)
Sandstone (with potential Arkose/Lithic characteristics)
Arenite (Sedimentary rock composed of sand-sized grains)
Chert (Common Variety, Jasper)
Microcrystalline Quartz (SiO2)
Polished black stone egg, probably black obsidian
Obsidian, a natural volcanic glass; composition primarily silica-rich glass (approximately SiO₂), with variable iron and other trace elements
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
Quartzite
Metamorphosed Quartz Sandstone
Greenstone
Metamorphic mafic rock (chlorite-actinolite-epidote schist)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Granite / Diorite (Granodiorite)
Granodiorite / Quartz Diorite
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
Pearl-and-gemstone insect brooch
Pearl: nacre (aragonite, CaCO₃); colored stones are likely synthetic or natural corundum/spinel/glass, not determinable from the image
Red Chert (Jasper)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Mica Schist
Mica Schist (principally Biotite/Muscovite, Quartz, and Feldspar)
Sandstone
Sandstone (clastic sedimentary rock, predominantly SiO2)
Siltstone Pebble
Siltstone (composed of microscopic quartz and clay minerals)
Granite
Plutonic Igneous Rock (composed typically of SiO2, Al2O3, K2O, Na2O, CaO)
Chert
Chert (Microcrystalline Quartz, SiO2)
Chert (varietal Flint)
Microcrystalline quartz (SiO2)
Sandstone
Sedimentary Rock (Quartz Sandstone)
Synthetic Marbled Aggregate (Footwear Component)
Ethylene-vinyl acetate (Croslite™)
Red Sandstone
Arenite (Ferruginous Sandstone)
Chert
Microcrystalline quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Granite
Phaneritic Plutonic Felsic Rock
Chalcedony (Common Opal or Agate variant)
Silicon dioxide (SiO2) with trace hydration
Diamond
Diamond (Pure Carbon, C)