Cobalt Blue Sea Glass
Amorphous Silica Glass (SiO2 + CoO)
mineraloid / anthropogenic material
Category
Mineral (Specifically A Mineraloid)
Browse mineral (specifically a mineraloid) specimens identified by the Rock Identifier community.
Obsidian
Volcanic glass (mainly SiO2 with inclusions)
igneous
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
igneous
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (70–75% SiO2)
Igneous
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
mineraloid
Obsidian
Volcanic glass
igneous
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
sedimentary
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (mostly SiO2)
igneous
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
igneous
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
igneous
Limonite (Ironstone Concretion)
Limonite (Hydrated iron(III) oxide-hydroxide, mixtures of FeO(OH)·nH2O)
sedimentary
Amber
Succinite (specifically for Baltic amber); Complex mixture of organic compounds (C10H16O)
Organic Mineraloid
Moonstone (Green Moonstone / Garnierite)
Potassium Aluminum Silicate (KAlSi3O8) with inclusions of Garnierite
mineral
Limonite (with Pyrite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
mineral
Obsidian
Volcanic Glass (SiO2 rich)
Igneous
Tektite (specifically Indochinite)
Tektite (Natural silica glass)
Mineraloid (Impact glass)
Obsidian (Gold Sheen)
Obsidian (SiO2 + impurities)
igneous
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
igneous
Mahogany Obsidian
Volcanic Glass (SiO2 + Fe2O3)
igneous
Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
igneous
Mahogany Obsidian
Volcanic Glass (Silicate: SiO2 + Fe2O3)
igneous
Mahogany Obsidian
Volcanic glass containing Magnetite/Hematite
igneous
Pink Satin Spar (Satin Spar Selenite Dyed)
Gypsum (CaSO4·2H2O)
mineral
Limonite (Iron Ore)
Hydrous ferric oxides (FeO(OH)·nH2O)
mineral
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)
igneous
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
mineral
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
mineral
Obsidian
Volcanic Glass (predominantly SiO2, approximately 70% or more)
igneous
Limonite Concretion
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
sedimentary
Obsidian
Volcanic Glass (predominantly SiO2)
igneous
Crazy Lace Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Amber
Succinite (with a generalized formula of C10H16O)
mineral
Yellow Ocher (Limonite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
mineral
Tumbled Moonstone
Feldspar (Orthoclase/Albite), KAlSi3O8
mineral
Moldavite
Silica glass with small amounts of aluminum, iron, and other elements
Mineraloid / Tektite
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
igneous
N/A - Image does not contain a rock or mineral
Anthropogenic textile material
Non-geological
Limonite with Quartz (Gossan)
Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)
Mineral
Obsidian
Volcanic Glass (Silicon Dioxide with impurities)
igneous