River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Sedimentary Rock (possibly composed of various minerals)
Category
Metamorphic Rock
Browse metamorphic rock specimens identified by the Rock Identifier community.
Lapis Lazuli
Lapis Lazuli (Complex silicate rock containing Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Pyrite, and Calcite)
metamorphic
Rhodonite
Manganese Inosilicate (MnSiO3), often with Ca, Fe, Mg, Zn
Mineral
Blue Quartz
Quartz (SiO2) with inclusions
Mineral
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Basalt (Vesicular)
Basalt (Extrusive Volcanic Rock)
igneous
Yellow Aventurine (Yellow Quartz)
Silicon Dioxide (SiO2) with inclusions of Muscovite or Mica
Mineral (variant of Quartz)
Geode with Quartz and possibly Jasper/Hematite
Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides
Mineral/Sedimentary Geode
Aquamarine and clear quartz
Aquamarine (Be3Al2Si6O18), Quartz (SiO2)
Mineral
Green Aventurine
Silicon Dioxide (SiO2) with Chromium-rich Fuchsite mica
mineral
Green Aventurine
Silicon Dioxide (Quartz) with Fuchsite inclusions (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Magnetite
Magnetite (Fe3O4)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Basalt with inclusion
Basalt (Aphanitic-Porphyritic texture)
igneous
Basalt with Scoria
Amygdaloidal Basalt / Vesicular Basalt
igneous
Druzy Quartz on Chert/Chalcedony
Silicon Dioxide (SiO2)
mineral
Quartz Geode (likely within Limestone or Dolomite matrix)
Quartz (SiO₂)
Mineral within a Sedimentary Rock
Pyrite in Quartz (Drill Core)
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2) inclusions
igneous/metamorphic (hydrothermal)
Basalt
Basalt (Mafic volcanic rock)
igneous
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Mineral
Lapis Lazuli (blue bead) and Moss Agate (green heart)
Lapis Lazuli (lazurite-based rock) and Moss Agate (SiO2 with manganese/iron inclusions)
metamorphic (Lapis) and sedimentary/igneous assoc. (Moss Agate)
Rhodonite
Manganese Inosilicate (MnSiO3)
Mineral
Quartz on Chlorite Schist
Chlorite Schist (Mg,Fe)3(Si,Al)4O10(OH)2 with Quartz (SiO2)
metamorphic
Amber-bearing Coal/Sedimentary Rock
Bituminous coal or carbonaceous siltstone with Fossilized Tree Resin (C10H16O)
sedimentary
Basalt
Basalt
igneous
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
sedimentary
Desert Varnish on Sandstone
Ferromanganese coating on Quartz Arenite
sedimentary
Pyrite (on the right) and Magnetite or Hematite (on the left)
Iron Sulfide (FeS2) and Iron Oxide (Fe3O4 or Fe2O3)
mineral
Osumilite in Granite Matrix
(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30
mineral
Amethyst
Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities
Mineral
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
mineral
Orange Calcite (likely polished specimen)
Calcite
Mineral
Quartz (in matrix)
Quartz (SiO₂)
mineral
Dumortierite Quartz
Dumortierite (Al7BO3(SiO4)3O3 / inclusion in SiO2)
metamorphic
Green Tourmaline
Elbaite (part of Tourmaline group), Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4
mineral
Yellow Sapphire or Citrine
Al2O3 (Corundum) or SiO2 (Quartz)
mineral
Basalt
Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt Cobble
Aphanitic Mafic Igneous Rock (Basalt)
igneous