Ruby
Corundum (Al2O3 with Chromium traces)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Ruby
Corundum (Al2O3 with Chromium traces)
Magnetite
Magnetite (Fe3O4)
Quartzite Pebble
Quartzite (SiO2)
Quartzite
Quartzite (SiO2)
Quartz (likely Herkimer Diamond style)
Silicon Dioxide (SiO2)
Aquamarine (Beryl)
Beryllium aluminum silicate (Be3Al2Si6O18)
Kyanite in Quartz
Al2SiO5 in SiO2
Quartzite
Quartzite (SiO2)
Anthracite Coal
Anthracite
Red Jasper (Opaque Chalcedony)
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Chert (variations include Flint/Jasper)
Chert (SiO2)
Agate (Common Chalcedony)
Silicon Dioxide (SiO2)
Asphalt (Bituminous Concrete)
Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
Anthracite Coal
Anthracite
Anthracite Coal
Anthracite (Carbon C)
Smoky Quartz
Smoky Quartz (SiO2)
N/A - Image does not contain a rock or mineral
Anthropogenic textile material
Basalt
Basalt (SiO2 percentage between 45% and 52%)
Emerald
Beryl (Be3Al2Si6O18), specifically the green variety colored by chromium or vanadium
Quartzite (or Quartz Rich Conglomerate)
Quartzite (SiO2 silicon dioxide)
Green Calcite
Calcite (Calcium Carbonate, CaCO3)
Quartzite River Rock
Quartzite (SiO2)
Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)
Calcite
Yellow Quartzite (River Pebble)
Quartzite (primarily SiO2)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Chakra Tumbled Stone Set
Various (including Amethyst [SiO2], Sodalite [Na8(Al6Si6O24)Cl2], Green Aventurine [SiO2], Red Jasper [SiO2], etc.)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Hematite
Hematite (Iron(III) oxide, Fe2O3)
Biotite Mica
Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2
Quartzite
Quartzite (primarily SiO2)
Quartzite (Gold/Tan River Cobble)
Quartzite (composed primarily of crystalline SiO2)
Anthracite Coal
Anthracite (Carbon)
Opaline Glass (Opalite)
Synthetic Silicon Dioxide Glass
White Agate (Chalcedony)
Silicon Dioxide (SiO2)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Hypersthene (or Enstatite/Ferrosilite)
Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)
Quartzite (Milky)
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Blue Kyanite
Kyanite (Al2SiO5)
Green Fluorite
Calcium Fluoride (CaF2)