Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Category
Browse sedimentary (or mineraloid) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Obsidian
Volcanic Glass (SiO2)
Red Sandstone
Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)
Amber with Inclusion
Succiniferous fossil resin (C10H16O)
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
Obsidian
Obsidian (volcanic glass), primarily SiO2 (silicon dioxide)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (70–75% SiO2)
Obsidian
Amorphous volcanic glass (primarily SiO2)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic glass (mainly SiO2 with inclusions)
Black Obsidian
Volcanic Glass (SiO2 + impurities like Fe3O4)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Snowflake Obsidian
Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions
Obsidian
Volcanic Glass (SiO2)
Black Pearl (Tahitian Pearl)
Aragonite / Calcite (CaCO3) with Conchiolin
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
Obsidian
Volcanic Glass (70-75% SiO2)
Snowflake Obsidian
Volcanic glass containing Spherulitic Cristobalite (SiO2)
Mahogany Obsidian
Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)
Gold Sheen Obsidian
Obsidian (volcanic glass with SiO2 + gas inclusions)
Obsidian
Volcanic Glass (SiO2)
Black Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Limonite (Yellow Ochre)
Limonite (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)
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Glass
Amorphous Silicon Dioxide (SiO2)
Amber
Succinite (C10H16O)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Pearl
Calcium Carbonate (Aragonite or Calcite) and Conchiolin
Opalite
Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)
Amber
Succinite (a specific common type) or Fossilized Tree Resin (C10H16O)
Amber
Succinite (organic fossilized resin)
Amber
Succinates (Organic compound: C10H16O)
Ambergris
Ambergris (Coprolite-adjacent/Organic secretion)
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (Industrial Byproduct)
Fulgurite
Lechatelierite (Silica glass), typically SiO2
Black Pearl (Tahitian Type)
Aragonite / Conchiolin composite (CaCO3)
Fulgurite
Luechatelierite (SiO2 glass)