Serpentine
Serpentinite (rock), Serpentine group minerals (e.g., Antigorite, Lizardite, Chrysotile)
Metamorphic rock
Category
Igneous Rock
Browse igneous rock specimens identified by the Rock Identifier community.
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Quartz (Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Quartz Pebble (with Iron Inclusions)
Silicon Dioxide (SiO2)
mineral
Bumblebee Jasper
Hydrothermal Volcanic Rock (Primarily Calcite with Orpiment - As2S3, Realgar, and Pyrite)
igneous
Pink Granite
Phaneritic Acidic Plutonic Rock (primarily K-feldspar, quartz, and plagioclase)
Igneous
Biotite Mica
Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Granite
Granite (Felsic Plutonic Rock, consisting primarily of Quartz, Feldspar, and Mica)
Igneous
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite)
Metamorphic rock
Quartz Crystal Cluster
Quartz (Silicon Dioxide, SiO2)
mineral
Lepidolite in Quartz (Lithium-bearing Ore)
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2) and Quartz (SiO2)
igneous/mineral
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
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
mineral
Moonstone (bead form)
Potassium Aluminum Silicate (KAlSi3O8) - a variety of Orthoclase Feldspar
Mineral
Fluorite in Matrix
Fluorite (CaF2) within a host rock matrix
Mineral
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
Metamorphic Rock
Graphite
Graphite (Carbon, C)
Mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Schist
N/A (a rock type, not a mineral formula)
metamorphic
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Mineral
Corundum
Corundum (Al2O3)
Mineral
Clear Quartz (Rock Crystal)
Quartz (SiO₂)
Mineral
Gneiss (specifically a Banded Gneiss pebble)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Granite Gneiss
High-grade regional metamorphic rock (Quartz-Feldspar Gneiss)
metamorphic
Quartz
SiO₂ (Silicon Dioxide)
Mineral
Muscovite Mica
Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))
Mineral
Granite
Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Granite
Phaneritic plutonic rock (approx. 20-60% quartz, 35-90% feldspar)
igneous
Quartz (vein quartz)
SiO2 (Silicon Dioxide)
Mineral
Bumblebee Jasper
Fossiliferous Volcanic Rock (composed of Calcium Carbonate, Manganese Oxides, and Arsenic Sulfides)
igneous
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz Crystal
Quartz (SiO₂)
Mineral
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Mineral/Mineraloid within a rock matrix
White Quartz
Quartz (SiO2)
Mineral
Basalt
Basalt
Igneous
Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)
sedimentary
Quartz (likely a weathered/tumbled piece)
Quartz (SiO₂)
Mineral
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral