Coal (most likely Bituminous or Anthracite)
Coal (primarily composed of carbon with varying amounts of other elements)
Category
Browse anthropogenic (man made material mimicking sedimentary rock) specimens identified by the Rock Identifier community.
Coal (most likely Bituminous or Anthracite)
Coal (primarily composed of carbon with varying amounts of other elements)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Epidote in Quartz
Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)
Quartz (likely Milky Quartz or Chalcedony)
Quartz (SiO2 - Silicon Dioxide)
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various metal oxide impurities
Chakra Stone Tower (Composite Multi-Mineral)
Crystalline Silicon Dioxide composite (SiO2) with various inclusions
Red Jasper
Jasper (a variety of Quartz, SiO2)
Pebble (likely Quartzite or Chert)
Clastic Sediment, potentially composed of SiO₂ (Quartz)
Quartz Geode/Cluster
Quartz (SiO2)
Conglomerate
Conglomerate
Silicon Carbide (Carborundum)
Silicon Carbide (SiC) / Moissanite (natural)
Quartz
Quartz (SiO₂)
Opalite
Synthetic Glass (SiO2 + impurities)
Quartz
Quartz (SiO2)
Green Slag Glass (Cullet)
Amorphous Silica (Industrial Glass Byproduct)
Quartz
Quartz (SiO2, Silicon Dioxide)
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Quartz
Quartz (SiO₂)
Lapis Lazuli
A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
Chert (Jasper-like)
SiO2 (Cryptocrystalline Quartz)
Quartz
Quartz (SiO₂)
Dolomite
Dolomite (CaMg(CO3)2)
Quartz (variety of colors)
SiO2 (Silicon Dioxide)
Cobalt Blue Slag Glass
Amorphous Silicon Dioxide (anthropogenic) with Cobalt additives
Banded Chert
Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)
Red Jasper
Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Red Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO₂)
Pink Stained Rock (Likely Quartzite or Sandstone with Iron Oxide Staining)
Quartzite (metamorphic) or Sandstone (sedimentary); coloration likely due to hematite or other iron oxides.
Laterite
Laterite (primarily composed of hydrated oxides of iron and aluminum)
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Agate
Agate (a cryptocrystalline variety of Quartz, SiO₂)
Quartz Geode/Druzy Quartz
Quartz (SiO₂)
River Rock (Glacial Cobbles)
Fluvial Alluvium (Mixed lithology including Quartzite, Basalt, and Granite)
Shale
Shale
Banded Jasper (Chert)
Silicon Dioxide (SiO2) - variety of Chalcedony
Quartz (Float/Abraded)
Quartz (SiO₂)
Pink Tumbled Quartz (Dyed)
Silicon Dioxide (SiO2)
River Cobble (likely Sandstone or Siltstone type)
Sandstone or Siltstone (common rock types that form river cobbles)
Quartz (likely milky quartz or a stained variety)
Silicon Dioxide (SiO₂)