Boulder Opal
Hydrated Silica (SiO2·nH2O)
Category
Browse mineral (or mineraloid if microcrystalline) specimens identified by the Rock Identifier community.
Boulder Opal
Hydrated Silica (SiO2·nH2O)
Obsidian
Volcanic Glass (Amorphous Silica)
Black Obsidian
Obsidian (Volcanic Glass)
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (70–75% SiO2)
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Amber
Succinite (approximate formula C10H16O)
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
Amber
Succinite (C10H16O)
Pearls
Aragonite (calcium carbonate) and Conchiolin
Cobalt Glass Slug (Man-made Glass)
Amorphous Silica with Cobalt Oxide (SiO2 + CoO)
Amber
Succinates (C10H16O)
Amber
Succinite (organic fossilized resin)
Amber
Succinite (fossilized resin); C10H16O
Amber
Amber (Succinite), fossilized tree resin
Amber (with potentially inclusions)
Succinite (Fossilized Tree Resin)
Amber
Succinite (Fossilized Tree Resin)
Amber
Succinate (Fossilized Tree Resin)
Amber
Succinate (Succinite for Baltic varieties)
Amber
Succinite (organic hydrocarbon)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions
Black obsidian
Volcanic glass; predominantly silica-rich, noncrystalline SiO₂
Obsidian
Volcanic Glass (felsic composition)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Obsidian
Volcanic glass
Obsidian
Volcanic Glass (Silicon Dioxide with impurities)
Common Opal with Host Rock
Opal (Hydrated silica, SiO2·nH2O)
Amber
Succinite (C10H16O)
Amber
Succinite (fossilized resin)
White Precious Opal
Hydrated Silica (SiO2·nH2O)
Amber
Succinite
Amber
Succinite (C10H16O)
Precious Opal
SiO2·nH2O (Hydrated Silicon Dioxide)
Amber (Tumbled/Polished)
Succinite (Fossilized Tree Resin)
Amber
Succinite (C10H16O)
Amber
Succinite (specifically for Baltic Amber), Formula: C10H16O
Amber
Succinite (C10H16O)
Amber
Succinite (Resinous fossilized tree sap)
Amber / Copal
Fossilized Tree Resin (Succinate)
Obsidian
Obsidian (Volcanic Glass)
Limonite (Yellow Ochre)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Limonite (Ironstone) Concretion
FeO(OH)·nH2O (Hydrous ferric oxide)
Snowflake Obsidian
Volcanic glass containing Spherulitic Cristobalite (SiO2)