Travertine (often colloquially called Tufa)
Chemical Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Category
Organic Gemstone (Not A Rock Or Mineral)
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Chert (Arrowhead Preform or Point)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Vesicular Basalt (Scoria)
Basalt (Extrusive Igneous Rock)
igneous
Limonite (Iron Ore)
Limonite; FeO(OH)·nH2O
mineral
Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)
SiO₂ (silicon dioxide)
Sedimentary
Granite Pebble
Granite (composed primarily of Quartz, Feldspar, and Mica)
igneous
Milky Quartz with Inclusions
Quartz (Silicon Dioxide, SiO2)
mineral
Quartzite with inclusions
Metamorphic Rock (Mainly SiO2)
metamorphic
Quartz Geode (Cracked Open)
Quartz (Silicon Dioxide - SiO2)
mineral
Orca Agate (Blue Chalcedony)
Silicon Dioxide (SiO2)
mineral
Sunstone (Heliolite)
Plagioclase Feldspar ((Ca,Na)(Al,Si)4O8)
mineral
Banded Chert
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Chrysocolla in Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix
mineral
Quartz Vein in Host Rock (Gneiss/Schist)
Silicon Dioxide (SiO2) within a metamorphic matrix
metamorphic
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
sedimentary
Quartz-veined Sedimentary Rock
Hydrothermally veined Clastic Sedimentary Rock (SiO2 veins in Matrix)
sedimentary
Quartz Vein in Siltstone
SiO2 (Quartz) on clastic sedimentary matrix
sedimentary
Labradorite
Labradorite (Ca, Na)(Al, Si)4O8
mineral
Collection of Minerals and Ores
Various (e.g., Uraninite (U3O8), Carbon (C), Native Gold (Au), Hematite (Fe2O3), Galena (PbS), etc.)
mineral
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Amethyst
Silicon Dioxide (SiO2) containing iron impurities
mineral
Synthetic Wolf Plush (Non-mineral)
Canis lupus similis (Prop material: Polyester & Synthetic fibers)
Synthetic material/Textile
Blue Lace Agate
Chalcedony (SiO2) with trace inclusions
mineral
Quartz Veinated Sandstone or Siltstone
Silicon Dioxide (SiO2) within a clastic sedimentary matrix
sedimentary
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
White Marble
Recrystallized Calcite (CaCO3)
metamorphic
Jasper
Agate/Jasper (Microcrystalline Quartz, SiO2)
sedimentary
Septarian Nodule (Dragon Stone)
Septarian Concretion (CaCO3 with Siderite and Calcite)
sedimentary
Septarian Nodule (Dragon Stone)
Septarian Geode (CaCO3 + Mg + Fe)
sedimentary
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Mineral
Sandstone (likely Siltstone or fine-grained Sandstone)
Sedimentary Rock (Clastic)
sedimentary
Basalt with Calcite Veins
Basalt (containing CaCO3 inclusions)
igneous
Breciated Limestone with Calcite Veins
Sedimentary Breccia (CaCO3)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Olivine (Peridot)
Magnesium Iron Silicate ((Mg, Fe)2SiO4)
mineral
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock with secondary mineral infilling)
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt (Ca-rich Plagioclase, Pyroxene, and Olivine)
igneous
Sandstone (with banding)
Arenite (primarily SiO2)
sedimentary
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Emerald in Matrix
Emerald (Beryllium Aluminum Silicate), Be3Al2(SiO3)6
mineral
Granite
Granite (Felsic Plutonic Rock)
igneous