Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
Category
Browse mineral (or mineraloid if microcrystalline) specimens identified by the Rock Identifier community.
Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
Amber
Succinicum (Organic Gemstone - Resinite)
Amber
Succinite (Carbon-based organic compound; approximate formula C10H16O)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Pearl (Biogenic Mineraloid)
Calcium carbonate (Aragonite) and Conchiolin, CaCO3
Bumblebee Jasper
Anhydrite-Aragonite mixture with Orpiment and Realgar
Opal (Precious Opal)
Hydrated Silica (SiO2·nH2O)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Amber (Copal)
Succinate (Fossilized Tree Resin)
Obsidian (black volcanic glass)
Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides
Likely obsidian (rough fragment)
Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich, noncrystalline)
Obsidian
Volcanic Glass (Amorphous SiO2)
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
Fire Opal (in Matrix)
Hydrated Silica (SiO2·nH2O)
Mahogany Obsidian
Volcanic glass (Silicon Dioxide with Hematite/Magnetite inclusions)
Snowflake Obsidian
Spherulitic Volcanic Glass (SiO2 + impurities)
Amber
Succinite (a specific common type) or Fossilized Tree Resin (C10H16O)
Black Opal (Triplet)
Hydrated Silica (SiO2·nH2O)
Obsidian
Obsidian (Volcanic Glass)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
White Opal (Common)
Hydrated Silica (SiO2·nH2O)
Common Opal (Potch)
Hydrated Silica (SiO2·nH2O)
Amber (likely a small rough amber piece)
Fossilized plant resin; amber is an organic mineraloid, not a crystalline mineral
Yellow amber beads
Amber (fossilized tree resin; organic mineraloid, not a true mineral)
Yellow-orange amber
Fossilized tree resin; amber is an organic mineraloid, not a true mineral
Amber (polished piece)
Fossilized tree resin; amber is an organic mineraloid, not a true mineral
Mahogany Obsidian
Obsidian (SiO2 + Fe2O3)
Snowflake Obsidian
Volcanic Glass (spherulitic Obsidian) - SiO2 (with Cristobalite inclusions)
Obsidian
Volcanic glass (silica-rich rhyolitic melt; primarily SiO₂)
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Amber (Copal)
Succinate (Fossilized Resin)
Amber / Copal
Succinite (fossilized tree resin)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Obsidian
Volcanic glass (Amorphous silicon dioxide)
Obsidian
Volcanic glass
Mahogany Obsidian
Volcanic Glass (SiO2 with Fe/Mg oxides)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)