Gold Sheen Obsidian
Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)
igneous
Category
Mineraloid (Human Made Geological Specimen)
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)
Mineral
Chert (specifically a Worked Flint/Knapped Flake)
Chert / Flint (Microcrystalline Quartz, SiO2)
sedimentary
Amber
Succinite (fossilized resin); C10H16O
mineraloid
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineral
Obsidian
Obsidian (Volcanic Glass)
Igneous
Chert (with Desert Varnish/Iron Stain)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint or Jasper locally)
Chert (Microcrystalline Quartz, Formula: SiO2)
sedimentary
Amethyst
Amethyst (Silicon Dioxide - SiO2 with Iron impurities)
mineral
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Obsidian
Volcanic Glass (SiO2)
igneous
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Chert (Flint variety)
Chert (SiO2)
sedimentary
Snowflake Obsidian
Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions
igneous
Dzi Bead (Etched Chalcedony)
Cryptocrystalline Quartz (SiO2) with chemical etching
mineral
Ceramic or Polished Stone Heart (Anthropogenic Material)
Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)
Synthetic/Anthropogenic Mineraloid
Concrete Paver (Artificial Cementitious Rock)
Hydrated Portland Cement Aggregate
Sedimentary (Synthetic)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
mineraloid
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
mineral
Citrine Quartz
Citrine (Silicon Dioxide, SiO2)
mineral
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
tektite
Sandstone (likely Quartzose)
Clastic sedimentary rock (SiO2 primary)
sedimentary
Chert (Common Opal/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Titanium Aura Quartz (Bismuth-coated Druzy)
Silicon Dioxide (SiO2) with Titanium/Metal vapor coating
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
igneous
Obsidian
Obsidian (volcanic glass; primarily SiO2)
igneous
Chalk
Carbonate rock (mainly CaCO3)
sedimentary
Slag Glass
Vitreous Silicate Residue
industrial byproduct (anthropogenic rock)
Ironstone Concretion (Pot Stone)
Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)
sedimentary
Moonstone
Orthoclase Feldspar ((K,Na)AlSi3O8) with Albite inclusions
mineral
Aura Quartz (Pink/Rose Aura Quartz)
Silicon Dioxide (SiO2) bonded with Platinum and/or Silver
mineral
Diamond (Cluster Ring)
Carbon (C)
mineral
Obsidian with Mahogany Phasing
Volcanic Glass (SiO2 + Fe2O3)
igneous
Obsidian
Volcanic Glass (SiO2)
igneous
Chert (and Flint)
Silicon Dioxide (SiO2)
sedimentary
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
igneous
Man-made Glass (Tumbled/Shaped)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Mineraloid (synthetic)
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
sedimentary
Granite
Phaneritic Felsic Igneous Rock
igneous
Opalite
Opalescent Glass (SiO2 + coloring agents)
Mineral (Synthetic/Man-made)