Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Category
Browse granite specimens identified by the Rock Identifier community.
Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Sandstone
Arenite (composed primarily of SiO2)
Anthracite Coal
Anthracite (Highly Metamorphosed Coal)
Sandstone
Arenite (primarily SiO2)
Chert (Arrowhead/Tool variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Quartz Vein / Milky Quartz
Silicon Dioxide (SiO2)
Conglomerate
Conglomeratic Sandstone
Chert (Flint)
Silicon dioxide (SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone (lithic wacke/arenite)
Clastic sedimentary rock (primarily SiO2)
White Quartz Pebble
Silicon Dioxide (SiO2)
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Jasper in Rhyolite matrix
Silicon Dioxide (SiO2) with various inclusions in Felsic Igneous matrix
Strawberry Quartz
Silicon Dioxide (SiO2) with inclusions of Goethite or Hematite
Chert (Chert Nodule with Cortex)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Caribbean Calcite
Calcite and Aragonite (CaCO3)
Chert (often called Flint)
Microcrystalline Quartz (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Chert / Flint
Cryptocrystalline Quartz (SiO2)
Smoky Quartz
Silicon Dioxide (SiO₂)
Milky Quartz
Silicon Dioxide (SiO2)
Quartzite (River Stone)
Quartzite (SiO2)
River Stone (likely Basalt or Chert)
Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (containing fossil leaf impression)
Microcrystalline silicon dioxide (SiO2)
Basalt (Polished)
Extrusive mafic igneous rock
Emerald in Matrix
Beryl (Be3Al2Si6O18) with trace amounts of Chromium/Vanadium
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of Iron Oxide)
Quartzite
Quartzite (SiO2)
Fossilized Shark Tooth
Fossilized Elasmobranchii tooth (likely Odontaspis or Carcharias)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
Specular Hematite (Specularite)
Iron(III) oxide (Fe2O3)
Yellow Topaz (Imperial or Precious Topaz)
Al2SiO4(F,OH)2 (Aluminum Silicate Fluoride Hydroxide)
Jasper Conglomerate
Jasperoid Conglomerate (predominantly SiO2 with iron oxide impurities)
Amethyst (Tumbled)
Amethyst (Silicon Dioxide with Iron impurities) - SiO2
Ocean Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
Chert (Jasper/Brown Chert)
Silicon Dioxide (SiO2)