Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Category
Browse igneous and sedimentary mixture specimens identified by the Rock Identifier community.
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Calcite
Calcite (CaCO3)
Mexican Crazy Lace Agate
Silicon Dioxide (SiO2) with iron and aluminum inclusions
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2)
Yellow Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
White Agate (Chalcedony)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Quartz Pebble (Milky and Gray)
Quartz (Silicon Dioxide, SiO2)
Quartz (likely milky quartz or a stained variety)
Silicon Dioxide (SiO₂)
Carnelian
Chalcedony (SiO2) with iron oxide impurities
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Quartz
Quartz (SiO₂)
Hematite
Hematite (Fe2O3)
Quartz Vein in Host Rock (Breccia/Rhyolite)
Silicon Dioxide (SiO2) with matrix
Quartz
Silicon Dioxide (SiO2)
Calcite
Calcite (Calcium Carbonate, CaCO3)
Schist
N/A (a rock type, not a mineral formula)
Pumice
Pumice (volcanic rock)
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Orange Quartz with Hematite inclusions
Quartz (SiO2) with Hematite (Fe2O3) inclusions
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(OH)₄(BO₃)₃Si₆O₁₈)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
Ferruginous Sandstone (with Iron Oxide staining)
Clastic Sedimentary Rock - Quartz Arenite/Wacke
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Marble
Metamorphosed Limestone/Dolomite
Quartz Pebble
Silicon Dioxide (SiO2)
Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)
Calcite
Black Tourmaline (Schorl)
Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3)(OH)3(OH))
Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)
Quartz (SiO₂ - Silicon Dioxide)
Banded Gneiss
Gneiss (variable mineral composition)
Chalcopyrite
Chalcopyrite (CuFeS2)
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Blue Quartz
Quartz (SiO2) with inclusions
Moonstone
Adularia (orthoclase feldspar variety)
Rose Quartz
Rose Quartz (SiO2)
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)