Sandstone
Arenite (primarily SiO2 with trace Fe2O3)
sedimentary
Category
Man Made Material
Browse man made material specimens identified by the Rock Identifier community.
Red Jasper
Red Jasper (variety of Chalcedony, SiO₂)
Mineral
Limestone (Grey and White specimens)
Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Igneous
Sandstone
Arenite (a specific type of sandstone with less than 15% matrix)
Sedimentary rock
Sandstone
Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)
Sedimentary Rock
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Mineral
BROWN GRANITE (likely 'Tan Brown' or similar)
Granite (specifically a variety rich in orthoclase feldspar, often with biotite and possibly hornblende)
igneous
Chert (Yellow/Brown variety)
Chert (SiO2)
sedimentary
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Mineral, Organic Gemstone
Calligraphy Stone
Mariam Jasper (Fossiliferous Limestone composed of Hematite and Shell remains)
sedimentary
Talc
Talc (Mg₃Si₄O₁₀(OH)₂)
Mineral
Quartz
Quartz (SiO₂)
Mineral
Jasper (yellow/cream variety)
SiO₂ (Cryptocrystalline Quartz)
Sedimentary
Granite (weathered pebble)
Granite (plutonic igneous rock)
Igneous
Chert (Fossiliferous)
Silicon dioxide (SiO2)
sedimentary
Diamond
Carbon (C), specifically a solid form of the element carbon with atoms arranged in a crystal structure called diamond cubic.
Mineral
Sandstone
Arenite (SiO2 based with various mineral cements)
sedimentary
Seraphinite
Clinochlore (Mg,Fe)5Al(AlSi3O10)(OH)8 - specific variety for Seraphinite due to its fibrous inclusions and chatoyancy.
Mineral
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with iron oxide cement)
sedimentary
Sandstone
Arenicola (comprising mostly Quartz, SiO2)
sedimentary
Sandstone
Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)
Sedimentary Rock
Quartz Geode/Cluster
Quartz (SiO2)
mineral
Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone (likely Fossiliferous)
Arenite / Sedimentum arenaceum
sedimentary
Granite
Phaneritic Felsic Igneous Rock
igneous
Laterite
Laterite (primarily composed of hydrated oxides of iron and aluminum)
Sedimentary Rock (as a residual soil/rock, it's often considered a type of sedimentary rock due to its formation from weathering, though it can cross into soil science)
Sandstone Chert/Quartzite
Silicon Dioxide (SiO2) - Sedimentary Sandstone / Orthoquartzite
sedimentary
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Veined Quartz
SiO2 (Silicon Dioxide)
Mineral
Red Jasper or Chert
Jasper (SiO2, a variety of chalcedony with iron oxide impurities), Chert (SiO2)
sedimentary
Quartz (likely Milky Quartz)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Quartz
Quartz (SiO₂ - Silicon Dioxide)
mineral
Sandstone
Sandstone (clastic sedimentary rock)
Rock
Sandstone (Pebble/Cobble)
Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)
Sedimentary
Quartz (Float/Abraded)
Quartz (SiO₂)
Mineral
Peridot
Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)
Mineral
Quartz
Quartz (SiO2)
Mineral
Granite
Granite (a common rock type, not a single mineral; composed primarily of Quartz, Feldspar (Orthoclase and Plagioclase), and Mica (Biotite and/or Muscovite) and/or Amphibole)
Igneous
Cockle Shell (Fossil or Recent)
Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)
Sedimentary (Biogenic, a type of fossil)