Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Category
Browse organic mineraloid specimens identified by the Rock Identifier community.
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (70–75% SiO2)
Black Obsidian
Obsidian (Amorphous Silicon Dioxide)
Snowflake Obsidian
Volcanic Glass with Cristobalite Inclusions
Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Amber
Fossilized Tree Resin (Succinite)
Obsidian
Obsidian (Volcanic Glass)
Mahogany Obsidian
Obsidian (volcanic glass with hematite/magnetite inclusions)
Black Obsidian
Obsidian (Volcanic Glass, SiO2+)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Black Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite/Goethite Concretion
Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)
Obsidian
Obsidian (Volcanic Glass)
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite (Iron Ore)
Limonite (Hydrated iron oxide - FeO(OH)·nH2O)
Common Opal
SiO2·nH2O (Hydrated Silicon Dioxide)
Green Opal
Hydrated amorphous silica (SiO2·nH2O)
Green Opal or Yellow Opal
Hydrated Silica (SiO2·nH2O)
Green Opal
Hydrated amorphous silica (SiO2·nH2O) with inclusions
Cobalt Glass Slug (Man-made Glass)
Amorphous Silica with Cobalt Oxide (SiO2 + CoO)
Opalite
Synthetic Glass (Amorphized Silicon Dioxide)
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Tektite (Indochinite)
Impact Glass (SiO2 + Al2O3)
Slag (Industrial Glass)
Anthropogenic Amorphous Vitreous Silicate
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
Conch Pearl
Calcareous concretion (CaCO3)
Amber
Succinite (approximate formula C10H16O)
Tektite (Indochinite)
Tektite (SiO2 + Al2O3)
Sea Glass (Frosted Quartz/Glass)
Amorphous Silicon Dioxide (SiO2)
White Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Black Opal
Hydrated silica (SiO2·nH2O)
Amber
Succinite (C10H16O)
Fulgurite
Liesegang (Fulgurite)
Opal
Hydrated silica (SiO2·nH2O)
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial Man-made)
Amber (specifically Burmese Amber or Burmite)
Succiniferous fossil resin (C10H16O)
Fulgurite
Fulgurite (Lechatelierite-rich fused silica)