Quartz Geode
Silicon Dioxide (SiO2)
mineral
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
mineral (silicate-replaced organic material)
Black Onyx
Silicon Dioxide (SiO2)
mineral
Lapis Lazuli
Lapis lazuli (primary component: Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Quartz Geode
Silicon Dioxide (SiO2)
Mineral / Sedimentary
Sandstone
Quartz Sandstone (predominantly)
Sedimentary
Lapis Lazuli
Lapis Lazuli (Primary mineral: Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Pearl and Garnet Glass
Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass
mineral and glass
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
sedimentary
Gold and Silver (in jewelry form)
Gold (Au) and Silver (Ag)
mineral
Nephrite Jade
Tremolite-Actinolite solid solution, Ca2(Mg,Fe)5Si8O22(OH)2
metamorphic
Nephrite Jade
Tremolite-Actinolite solid solution Ca2(Mg,Fe)5Si8O22(OH)2
metamorphic
Nephrite Jade
Tremolite-Actinolite solid solution Ca2(Mg,Fe)5Si8O22(OH)2
metamorphic
Red Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO₂)
Sedimentary Rock
Pearls
Aragonite (calcium carbonate) and Conchiolin
Mineraloid
Brown Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO2)
Mineral, specifically a variety of Quartz
Black Obsidian
Obsidian, SiO2 (amorphous)
Igneous rock (Volcanic glass)
Obsidian
Amorphous volcanic glass (70-75% SiO2)
igneous
Shungite
Shungite (Amorphous Carbon)
mineral
Obsidian
Volcanic glass (high silica SiO2)
igneous
Snowflake Obsidian
Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)
igneous
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Fire Opal (Common/Precious in Matrix)
Hydrated Silica (SiO2·nH2O)
mineral
Druzy Quartz Geode (likely Smokey Quartz variety)
Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.
Mineral structure/Rock
Quartz Geode (partially formed/chalcedony with iron staining)
Quartz (SiO2) with Chalcedony (cryptocrystalline quartz) and likely Iron Oxides/Hydroxides
Mineral/Sedimentary Rock Feature
Jasper, Agate, Quartz Mix (Polished Beads)
SiO₂ (Silicon Dioxide) for Quartz. Jasper and Agate are cryptocrystalline varieties of Quartz.
Mineral/Semiprecious Gemstone (variety of Quartz)
Red Jasper (possibly)
Jasper (a variety of Chalcedony, SiO2)
Mineral
Amber (Simulated/Faturan Style)
Resin mix (Likely Phenolic/Celluloid if synthetic, Succinite if natural)
Organic Gemstone (not a mineral)
Obsidian (Gold Sheen)
Obsidian (SiO2 + impurities)
igneous
Peridot (likely, based on color and appearance)
Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)
Mineral
Obsidian
Amorphous volcanic glass (primarily SiO2)
igneous
Chipped Glass/Plastic Fragment
Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic
Man-made material (simulant/artifact)
Obsidian
Volcanic glass (SiO2 - Silicon dioxide predominant composition)
Igneous
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions
igneous
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Limonite Concretion
Goethite-rich Concretion (FeO(OH))
sedimentary
Obsidian
Volcanic Glass (Amorphous SiO2)
igneous
Pumice
Pumice (Amorphous volcanic glass)
igneous
Pumice
Pumice (Amorphous volcanic glass)
igneous
Pumice
Pumice (Amorphous volcanic glass)
igneous
Obsidian
Obsidian (Amorphous volcanic glass)
igneous