Black Jasper
Black Jasper (Silicate mineral - SiO2)
Category
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Black Jasper
Black Jasper (Silicate mineral - SiO2)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Moss Agate
Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Quartz
Quartz (SiO₂)
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Travertine (Tufa)
Calcium Carbonate (CaCO3)
Amber (Copal)
Fossilized Tree Resin (C10H16O)
Quartz Geode/Cluster
Quartz (SiO2)
Sandstone
Arenite
Chrysocolla on Quartz/Rhyolite matrix
Hydrated copper phyllosilicate mineral: (Cu,Al)2H2Si2O5(OH)4·nH2O
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Hematite/Limonite oxides)
Sandstone
Arenite (composed primarily of SiO2)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Quartz with Limonite Staining
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Yellow Calcite
Calcium Carbonate (CaCO3)
Sunstone
Oligoclase (Plagioclase Feldspar Group) - (Ca, Na)(Al, Si)4O8
Amethyst
SiO2 (Silicon Dioxide) - Purple variety of Quartz
Precious Opal
Hydrated Silica (SiO2·nH2O)
Quartz (in a rock matrix)
Quartz (SiO2)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone (Wonderstone)
Arenite (composed primarily of SiO2 with Fe2O3 impurities)
Sandstone (likely Arkose or Quartz Sandstone)
Clastic sedimentary rock (primarily SiO2)
Note on Image Identification: Textile
N/A (Anthropogenic material)
Shungite
Shungite (carbon-rich Precambrian rock)
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
Sandstone
Sandstone (lithified arenite/wacke)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Peridotite (with Olivine and Pyroxene)
Ultramafic Magmatic Rock (Primary minerals: (Mg, Fe)2SiO4 and (Ca, Mg, Fe)2Si2O6)
Petrified Wood
Silicified Wood (SiO2)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2)
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
Quartz (Druzy) in host rock
SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)
Gneiss (Metamorphic Rock)
Gneiss