Sunstone
Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)
Category
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Sunstone
Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)
Chert (specifically Yellow/Tan Chert)
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone
Sandstone (Clastic Sedimentary Rock)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Moss Agate
Chalcedony (Silicon Dioxide / SiO2)
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Sandstone
Arenite (SiO2 based)
Chert / River Pebble
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Sandstone (Banded)
Clastic Sedimentary Rock: Arenite
Chert (often called Flint when in chalk or limestone)
Silicon Dioxide (SiO₂)
Precious Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Asphalt Concrete (Bituminous Conglomerate)
Anthropogenic Bituminous Conglomerate
Petrified Wood
Silicified Wood (SiO2)
Fossil Coral (Favosites Honeycomb)
Favosites (Genus), Phylum Cnidaria, Class Anthozoa
Sandstone
Arenite (SiO2 based with mineral cement)
Chalcedony (Botryoidal or Tumbled)
Chalcedony (SiO₂)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Serpentinite (often called Jade or Nephrite substitute)
Serpentinite (composed primarily of Antigorite, Lizardite, or Chrysotile)
Chert (often called Flint in this context)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone (Ferruginous)
Sandstone (mainly SiO2 with Fe2O3 staining)
Petrified Wood
Silicified Wood (SiO2)
Chert (and Petrified Wood)
Silicon Dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Jasper
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Red Jasper
Red Jasper (variety of Chalcedony, SiO₂)
Chert (Nodule)
Silicon Dioxide (SiO2)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Sandstone (Ferruginous)
Arenite (Fe-rich)
Fossilized Coral
Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)
Quartz (likely tumbled or naturally water-worn)
Quartz (SiO₂ - Silicon Dioxide)
Gneiss (Banded Gneiss)
Gneiss
Chipped Glass/Plastic Fragment
Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic
Red Sandstone
Arenite (predominantly Quartz with Hematite cementation)
Amber
Succinite (organic hydrocarbon)
Sandstone
Arenite (SiO2 with various cementing agents)