Gneiss (specifically a Granitic Gneiss)
Gneiss (Composition: Quartz, Feldspar, Mica)
metamorphic
Category
Rock (Likely Sedimentary)
Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Laterite (iron-rich nodule, possibly Bauxite as a subtype)
Laterite (composed of various minerals including goethite, hematite, gibbsite, etc.)
Sedimentary
Chert (Iron-Stained)
Microcrystalline Quartz (SiO2)
sedimentary
African Turquoise (Jasper)
Polychrome African Jasper (often marketed as 'African Turquoise' due to its color, but it is not true turquoise)
Rock
Clear Quartz (Rock Crystal)
Quartz (SiO₂)
Mineral
Muscovite Mica
Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2
mineral
Slate
Foliated Metamorphic Rock (primarily composed of quartz, illite, and chlorite)
metamorphic
Jasper
Jasper (a variety of Chalcedony, SiO2)
Mineral
Leopardskin Jasper
Jasper (a variety of microcrystalline Quartz)
Sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
River Pebbles (Tumbled Quartz and Basalt)
Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt
igneous and sedimentary
Limonite-stained Quartz / Quartzite
Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)
sedimentary or metamorphic
Puddingstone
Conglomerate (specifically a type of jasper conglomerate or quartz conglomerate)
Sedimentary
Chert (Green variety)
Microcrystalline Opaline/Quartz (SiO2)
sedimentary
Slate
Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz / Chert
Silicon Dioxide (SiO2)
Mineral / Sedimentary
Asphalt (Bituminous Concrete)
Bituminous mix / Anthropogenic conglomerate
man-made composite (lithified equivalent of sedimentary)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Chert (specifically Iron-stained River Cobble)
Silicon Dioxide (SiO2)
sedimentary
Pumice
Pumice (volcanic rock)
Igneous
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
mineral
Asphalt (Bituminous Pavement Bit)
Bitumen-bound aggregate (Petrochemical-bound composite)
sedimentary (anthropogenic/technogenic)
Chert Pebble (Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Rock Salt / Halite Crust
Halite (Sodium Chloride, NaCl)
sedimentary
Quartz
Quartz (Silicon Dioxide - SiO2)
Mineral
Quartzite
Quartzite (SiO2)
Metamorphic
Chert (or possibly Flint)
SiO2 (Silicon Dioxide)
Sedimentary Rock
Jasper, possibly Brecciated Jasper or Ocean Jasper due to patterns and color
Silicon Dioxide (SiO2), a variety of Chalcedony
Sedimentary Rock
Red Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO₂)
Sedimentary Rock
Banded Iron Formation
Banded Iron Formation (BIF)
Sedimentary Rock
Quartzite
Quartzite (primarily composed of SiO O₂)
Sedimentary Rock
River Pebbles (Stream-rounded rocks)
Fluvial Detritus (varied mineralogy)
Mixed (predominantly sedimentary and igneous)
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Organic Gemstone/Biomineral
Quartzite
Quartzite
Metamorphic rock
Herkimer Diamond in Matrix
Quartz (SiO2) in Dolostone (CaMg(CO3)2)
sedimentary (host) / mineral (crystals)
Quartz
Quartz (SiO₂)
mineral