Conglomerate
Conglomerate (Rock composed predominantly of rounded clasts > 2mm)
sedimentary
Category
Metamorphic Rock (Primarily Composed Of Minerals)
Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.
Basalt
Extrusive Mafic Igneous Rock
igneous
Banded Gneiss
Gneiss (complex metamorphic silicate rock)
metamorphic
Serpentine
Serpentinite (group of minerals: (Mg,Fe,Ni,Al)3Si2O5(OH)4)
metamorphic
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe3Al6(BO3)3Si6O18(OH)4
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Osumilite in Granite Matrix
(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30
mineral
Quartz with Chlorite or Hornblende inclusions
Silicon dioxide (SiO2) with phyllosilicate or amphibole inclusions
metamorphic
Veined Limestone (Micrite) with Quartz/Calcite Veins
Calcium Carbonate (CaCO3) with Silicate or Carbonate inclusions
sedimentary
Sandstone (Quartz-rich)
Arenite (composed mainly of SiO2)
sedimentary
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
mineral
Sandstone (Pet Rock)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (Quartzite-rich River Cobble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Gneiss
Gneiss (a type of metamorphic rock)
Metamorphic Rock
Quartz (Milk Quartz / Massive Quartz)
Silicon Dioxide (SiO2)
mineral
Banded Agate
Agate (Cryptocrystalline variety of Quartz, SiO2)
mineral
Aventurine
Quartz (Aventurine variety)
Mineral
Bivalve Shell (Fossil or Contemporary)
Class Bivalvie (various genera and species of clams, cockles, etc.)
Sedimentary (Biogenic sediment or biological remain)
Ruby in Fuchsite
Corundum (Al2O3) in Fuchsite (K(Al,Cr)3Si3O10(OH)2)
Mineral
Blue Apatite
Apatite, Ca5(PO4)3(F,Cl,OH)
mineral
Marble
Recrystallized Calcite (CaCO3) Rock
metamorphic
Marble
Recrystallized Calcite / Dolomite (CaCO3)
metamorphic
Diamond
Diamond (Pure Carbon, C)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Black Sand (Magnetite Sand)
Magnetite-rich Placers (Fe3O4)
sedimentary
Mica Schist
Muscovite/Biotite Schist
metamorphic
Mixed Tumbled Gemstones and River Rocks
Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)
Mixed (Igneous, Sedimentary, Metamorphic, and Minerals)
Gneiss
Gneiss (a metamorphic rock)
Metamorphic
Basalt
Basalt (primarily composed of Plagioclase feldspar and Pyroxene)
igneous
Sandstone (Red/Brown Variety)
Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)
sedimentary
Granite
Granite (Phaneritic intrusive igneous rock; primarily SiO2 and Al2O3)
igneous
Serpentinite
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Labradorite (likely Black Labradorite or Larvikite)
Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.
Mineral/Igneous Rock
Sandstone (Quartz Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone
Arenite (Siliclastic sedimentary rock)
sedimentary
Biotite (Mica)
Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)
mineral
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
metamorphic
Moss Agate
Moss Agate (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is microcrystalline Quartz)
Sandstone (Glacial Cobble)
Arenite / Sedimentary Rock (primarily SiO2)
sedimentary
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Quartz-Veined Mudstone
Argillaceous Mudstone with Quartz Veining
sedimentary