Clear quartz crystal point
Quartz (silicon dioxide, SiO₂), likely a polished or cut crystal
Category
Browse mineral composite specimens identified by the Rock Identifier community.
Clear quartz crystal point
Quartz (silicon dioxide, SiO₂), likely a polished or cut crystal
Weathered river stones, likely basaltic andesite and related volcanic rocks
Fine-grained mafic/intermediate volcanic rocks; commonly basalt (plagioclase + pyroxene ± olivine) or andesite (plagioclase + pyroxene ± amphibole)
Quartz Pebble
Silicon Dioxide (SiO2)
Unakite Epidote-Granite
Unakite (Epidotized Granite)
Quartz Pebble
Silicon Dioxide (SiO2)
Orthoclase Feldspar
Potassium Feldspar (KAlSi3O8)
Quartz Pebble
Silicon Dioxide (SiO2)
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Greenstone / Epidosite
Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartzite
Hydrothermal Quartz or Quartzite (SiO2)
Quartz with Mafic Inclusions
Silicon Dioxide (SiO2) with host igneous matrix
Demitasse Granite (Diorite-Granite transition)
Intermediate Plutonic Rock (Granodiorite/Diorite mix)
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
Quartz (Yellow/Tan Quartzite Pebble)
Silicon Dioxide (SiO2)
Lapis Lazuli
Sodalite-rich metamorphic rock containing Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2
Quartz (Milky/Crystal variety)
Silicon Dioxide (SiO2)
Green Calcite
Calcite (CaCO3)
Peridotite
Ultramafic igneous rock
Granite and Igneous Rock Collection
Intrusive igneous rock / Granitoid
Schist with Quartz Veins
Schist with Quartz (SiO2)
Amazonite
Microcline (K(AlSi3O8))
Rhodochrosite
Manganese Carbonate (MnCO3)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Green Fluorite
Calcium Fluoride (CaF2)
Fluorite (Blue)
Calcium Fluoride (CaF2)
Green Fluorite
Calcium Fluoride (CaF2)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Kidney Stone
Calculus (Calcium oxalate/Calcium phosphate)
Limonite (Iron Ore)
Hydrated ferric oxide (FeO(OH)·nH2O)
Granite
Granite (Felsic intrusive igneous rock)
Sandstone Cobble
Arenite (Sandstone)
Basalt with Caliche Crust
Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating
Sandstone (likely Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
Satin Spar (Gypsum)
Hydrous Calcium Sulfate (CaSO4·2H2O)
Amygdaloidal Basalt
Amygdaloidal Basalt (extrusive volcanic rock with mineral inclusions)
Shark Tooth Fossil
Carcharodonta (order Lamniformes), likely Carcharias spp.
Blue Apatite
Fluorapatite / Apatite group (Ca5(PO4)3(F,Cl,OH))
Sandstone
Arenite