Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Category
Sedimentary Rock
Browse sedimentary rock specimens identified by the Rock Identifier community.
Boxwork Quartz / Septarian Jasper
Boxwork (SiO2 with iron oxide inclusions)
metamorphic
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Metamorphic Rock
Epidote in Quartz
Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)
Mineral
Granite
Granite
Igneous
Serpentinite
Serpentinite (composed primarily of minerals in the Serpentine group)
metamorphic
Basalt with Quartz/Calcite Vein
Amygdaloidal Basalt (matrix) with Mineral Vein filling
igneous
Quartz (in matrix)
Quartz (SiO₂)
mineral
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Mineral
Quartz Crystal (specifically a Double-Terminated variety)
Silicon Dioxide (SiO2) - Low Quartz
mineral
Quartz in Host Rock
Silicon Dioxide (SiO2) in Rhyolite or Granite matrix
igneous
Amphibolite
Amphibolite
metamorphic
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Vesicular Basalt (River Rock)
Afanitic Vesicular Basalt
igneous
River Rock (Basalt/Greywacke pebbles)
Fluvial gravel primarily composed of Mafic Volcanic Rock (Basalt) or Lithic Sandstone (Greywacke)
igneous and sedimentary
Clear Quartz (beads in a bracelet)
Quartz (SiO2)
Mineral
Pyrite
Pyrite (FeS2)
Mineral
Gold in Quartz Matrix
Native Gold (Au) with Quartz (SiO2) and Slate/Shale
mineral
K2 Jasper (Beads)
Granodiorite with Azurite and Malachite
igneous
Biotite Schist
Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Basalt
Mafic extrusive volcanic rock (composed primarily of Plagioclase feldspar and Pyroxene)
igneous
Glauconitic Sandstone (or Greensand)
Glauconitic Siliciclastic Rock (Containing (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Calcite
Calcite (CaCO₃, Calcium Carbonate)
Mineral
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Mineral / Sedimentary (often associated with volcanic hosts)
Quartz
Silicon Dioxide (SiO2)
Mineral
Granite (phaneritic background) with Limestone/Calcite carving
Felsic Igneous Plutonic Rock (background) / Calcium Carbonate (CaCO3) (carving)
igneous and sedimentary
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Unakite
Epidotized Granite (Composed of Orthoclase Feldspar, Epidote, and Quartz)
metamorphic
Andesite Porphyry
Andesite (extrusive volcanic rock)
igneous
Granite (Specimen: Logan Rock)
Phaneritic plutonic igneous rock (mainly Quartz, Feldspar, and Mica)
igneous
Quartz (Crystal/Druzy Quartz)
Quartz (SiO₂)
Mineral
Scoria
Extrusive Basaltic Scoria
igneous
Quartz Vein in Host Rock (Pebble)
Quartz (SiO2) with sandstone or siltstone matrix
metamorphic/igneous transition
Granite (Background) and Quartzite/River Pebble (Foreground Heart)
Phaneritic Felsic Igneous Rock (Granite background)
igneous
Greenschist
Greenschist (chlorite-epidote schist)
metamorphic
River Rock (Basalt)
Aphanitic Basaltic Rock
igneous
Unakite
Epidote-Feldspar rock
Metamorphic Rock
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Mineral (specifically, a variety of the mineral species Pyrope-Almandine Garnet)
Chalcedony (Banded/Mottled Variety)
Chalcedony (a cryptocrystalline variety of Quartz, SiO2)
Mineral
Granite
Granite
Igneous