Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2)
igneous
Category
Mineral Description (Anthropogenic Material)
Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.
Porphyritic Basalt (Chinese Writing Stone or Flower Stone)
Porphyritic Basalt / Porphyry
igneous
Snowflake Obsidian
Obsidian (volcanic glass) with Cristobalite inclusions
igneous
Conglomerate
Clastic Sedimentary (Conglomerate)
sedimentary
Fossiliferous Limestone
Fossiliferous Calclutite / Bio-calcarenite (CaCO3)
sedimentary
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of Iron Oxide)
metamorphic
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
metamorphic
Diabase (Greenstone)
Diabase (also known as Dolerite)
igneous
Coquina / Fossiliferous Limestone
Bioclastic Limestone (CaCO3)
sedimentary
Puddingstone
Conglomerate
Sedimentary
Quartzite pebble
Metamorphic rock (mainly SiO2)
metamorphic
Fossilized Sea Urchin (Echinoid)
Echinoidea (Fossil specimen, often replaced by Calcite or Silica)
sedimentary
River Pebble (Quartz-rich)
Silicon Dioxide (SiO2) with various inclusions
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Limestone
Calcareous sedimentary rock (primarily Calcium Carbonate, CaCO3)
sedimentary
Quartzite
Quartzite (predominantly SiO2)
metamorphic
Quartzite (River Pebble)
Quartzite (primarily SiO2)
metamorphic
Red Jasper
Jasper (SiO2 with Fe2O3 inclusions)
sedimentary
Limestone (specifically Grainstone or Micrite)
Calcium Carbonate (CaCO3)
sedimentary
Granite
Granite (composed mainly of Quartz, Feldspar, and Mica)
igneous
Bloodstone / Heliotrope
Silicon dioxide (SiO2) with inclusions
Mineral (variety of Chalcedony)
Granite Pebble
Granite (Phaneritic intrusive igneous rock consisting of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Bamboo Leaf Jasper
Silicified Siltstone or Jasper (SiO2)
sedimentary
Quartz Geode/Druzy Quartz
Quartz (SiO₂)
Mineral
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
sedimentary
White Marble
Recrystallized Calcite (CaCO3)
metamorphic
Ferrous Slag
Iron/Steel Slag (Complex Calcium-Alumino-Silicates)
Anthropgenic (Industrial Byproduct)
Green Calcite
Calcite (CaCO3)
mineral
Sandstone
Sandstone (lithified sand)
sedimentary
Pebble (likely a type of sandstone or quartzite pebble)
Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.
Sedimentary rock
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
metamorphic
Conglomerate (River Rock)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Green Aventurine
Silicon Dioxide with Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
metamorphic
Topaz
Topaz (Al2SiO4(F,OH)2)
Mineral
Fossiliferous Rock (likely Dinosaur Fossil in Matrix)
Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)
sedimentary
Chert (Jasper)
Microcrystalline Quartz (SiO2) with Iron Oxide inclusions
sedimentary
Granite
Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)
igneous
Limestone
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Slate
Slate (Foliated Metamorphic Rock)
metamorphic
Chert (Tan/Grey variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint when dark)
Microcrystalline silicon dioxide (SiO2)
sedimentary