White Opal (Common)
Hydrated Silica (SiO2·nH2O)
mineral
Category
Organic Mineraloid And Mineral
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Common Opal (Potch)
Hydrated Silica (SiO2·nH2O)
mineral
Mahogany Obsidian
Obsidian (SiO2 + Fe2O3)
igneous
Orange cabochon gemstone, likely amber or amber-like resin
Natural amber: fossilized plant resin (organic mineraloid), commonly succinite; exact identification requires testing
gemstone
Snowflake Obsidian
Volcanic Glass (spherulitic Obsidian) - SiO2 (with Cristobalite inclusions)
igneous
Obsidian
Volcanic glass (silica-rich rhyolitic melt; primarily SiO₂)
igneous
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Igneous
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
igneous
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Mineral
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
igneous
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Mineraloid
Obsidian
Volcanic glass (Amorphous silicon dioxide)
igneous
Obsidian
Volcanic glass
igneous
Mahogany Obsidian
Volcanic Glass (SiO2 with Fe/Mg oxides)
igneous
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
igneous
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
sedimentary
Green Opal
Hydrated amorphous silica (SiO2·nH2O) with inclusions
mineraloid
Sea Glass (Frosted Quartz/Glass)
Amorphous Silicon Dioxide (SiO2)
Mineraloid
Black Obsidian
Volcanic glass (Amorphous silicates)
igneous
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial byproduct)
mineraloid
Obsidian
Obsidian (principally SiO2 with MgO and Fe3O4)
igneous
Green Opal (Prase Opal)
SiO2 · nH2O (Hydrated Silicon Dioxide)
mineral
Opalite
Synthetic glass (SiO2 + metal additions)
mineraloid
Amber and Citrine Quartz
Succinite (Amber) and Silicon Dioxide (SiO2 / Citrine)
mineral
Amber
Succinite (fossilized resin, C10H16O)
mineral
Snowflake Obsidian
Obsidian with Spherulitic Cristobalite (SiO2)
igneous
Amber
Succinicum (C10H16O)
mineral
Petrified Wood
Silicified wood (Quartz replacement, SiO2)
fossil
Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
igneous
Mahogany Obsidian
Volcanic glass (SiO2 + Fe2O3)
igneous
Obsidian
Volcanic Glass (Amorphous silicon dioxide with trace impurities)
igneous
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineral
Precious Coral
Corallium rubrum (Calcium carbonate with trace carotene)
Organic gemstone / Sedimentary mineraloid
Amber
Resinite / Fossilized Tree Resin
mineral
Kidney Stone
Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)
mineral
Polished amber
Amber (fossilized plant resin; chiefly amorphous organic compounds)
gemstone
Amber cabochon pendant
Amber (fossilized tree resin; chiefly polymerized terpenoids)
gemstone
Opalite
Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)
mineral
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
sedimentary
Weathered Sedimentary Rock
Sedimentary Rock
Sedimentary
Fossilized Bone
Permineralized Vertebrate Bone
fossil