Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Mineral/Mineraloid within a rock matrix
Category
Mineraloid (Impact Glass)
Browse mineraloid (impact glass) specimens identified by the Rock Identifier community.
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions
igneous
Quartz (River Pebble)
Quartz (Silicon Dioxide - SiO2)
mineral
Rhodonite
Rhodonite (MnSiO3)
Mineral
Mahogany Obsidian
Obsidian (SiO2 + Fe2O3)
igneous
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineraloid
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Mineraloid
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
igneous
Obsidian
Obsidian (principally SiO2 with MgO and Fe3O4)
igneous