Geode (unopened) or Calcareous Nodule
Siliceous or Calcareous Concretion/Nodule
Category
Browse sedimentary like (industrial composite) specimens identified by the Rock Identifier community.
Geode (unopened) or Calcareous Nodule
Siliceous or Calcareous Concretion/Nodule
Quartzite
Quartzite (SiO2)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Quartzite
Quartzite (primarily SiO2)
Pumice
Pumice (a highly vesicular volcanic glass)
Diamond (or Diamond Simulant)
Carbon (C)
Diamond
Diamond (pure Carbon, C)
Olivine (Peridot when gem-quality)
Magnesium Iron Silicate, (Mg,Fe)2SiO4
Sandstone
Arenite (SiO2 principal)
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
Anthracite Coal
Anthracite
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2)
Dolomite on Prehnite (Saddle-shaped Dolomite)
Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]
Milky Quartz
Quartz (SiO2) with iron staining
Anthracite
Anthracite Coal
Milky Quartz with Mineral Inclusions
Silicon Dioxide (SiO2)
Druzy Quartz on Matrix
Silicon Dioxide (SiO2)
Quartz / River Cobble
Silicon Dioxide (SiO2)
Chalcedony or Chert/Jasper with secondary mineral staining
SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.
Basalt with Magnetite inclusions
Basalt (Mafic silicate rock) potentially containing Magnetite (Fe3O4)
Desert Rose
Gypsum (variety Selenite) or Barite: CaSO4 · 2H2O
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Blue Sapphire
Corundum (Al2O3)
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
Green Opal
Hydrated Silica (SiO2·nH2O)
Diamond (or high-refractive faceted gemstone)
Carbon; C
Diamond (appearing in jewelry)
Diamond (pure Carbon, C)
Serpentine
Serpentinite (complex of Mg, Fe, Ni, Al, Zn, Mn)Si2O5(OH)4
Quartzite
Quartzite
Fluorite
Calcium Fluoride (CaF2)
Green Quartzite (Aventurine-like)
Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)
Blue Sapphire
Corundum (Al2O3 with trace amounts of iron and titanium)
Smoky Quartz
Silicon Dioxide (SiO2) with natural radiation induced color centers
Kyanite (Blue or Blue-Grey)
Kyanite (Al2SiO5)
Slag (Industrial Glass/Metal Waste)
Artificial silicate/ferro-silicate byproduct
Pyrite
Iron Sulfide (FeS2)
Kyanite (Green and Blue varieties)
Kyanite (Al2SiO5)
Diamond
Diamond (pure Carbon, C)
Anthracite Coal
Anthracite C
Petrified Wood
Silicified Wood (primarily SiO2)
Scoria (Red Lava Rock)
Scoria
Garnet
Garnet Group (complex nesosilicates with general formula X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+, V3+)