Dalmatian Jasper
Feldspar porphyry (Microcline and Quartz with Arfvedsonite spots)
Category
Browse synthetic (not a rock or mineral) specimens identified by the Rock Identifier community.
Dalmatian Jasper
Feldspar porphyry (Microcline and Quartz with Arfvedsonite spots)
Basalt with Quartz/Calcite Vein
Basalt (Mafic Volcanic Rock with secondary mineralization)
Feldspar
Aluminosilicate (KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8)
Quartz Pebble
Silicon Dioxide (SiO2)
Iron-stained Quartzite / Agate
Silicon Dioxide with Iron Oxides (SiO2 + Fe2O3·nH2O)
Amethyst
Amethyst (SiO2 with iron impurities)
Rose Quartz
Silicon dioxide with traces of titanium, iron, or manganese (SiO2)
Basalt with Quartz Infill
Basalt (Mafic Extrusive Volcanic Rock)
Quartzite with Feldspar and Mica (Granitic Gneiss Pebble)
Metamorphic Rock / Quartzite / Granitic Gneiss
Quartz crystal pendant
Quartz (silicon dioxide, SiO₂), likely rock crystal or milky quartz
Garnet Schist
Almandine-bearing Mica Schist
Quartz Pebble
Silicon Dioxide (SiO2)
Unakite
Unakite (Metasomatized Granite)
Sandstone Pebble
Sandstone (Siliciclastic Sedimentary Rock)
Sandstone (Ferruginous)
Arenite (with Iron Oxide cement)
Sandstone
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Granite
Granite
Milky quartz fragment
Quartz (silicon dioxide, SiO₂)
Banded Gneiss
Gneiss (High-grade metamorphic rock)
Wonderstone (Banded Rhyolite)
Rhyolite (Silicon Dioxide with Iron Oxide impurities)
Quartz (Druzy)
Silicon Dioxide (SiO2)
Fossilized coral (likely honeycomb or branching coral)
Fossil coral; probable Scleractinia or Tabulata, composition mainly microcrystalline CaCO₃
Obsidian
Amorphous volcanic glass (primarily SiO2)
Sandstone (with Lichen)
Arenite (primarily SiO2)
Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)
Geode Nodules / Keokuk Geode
Quartz / Chalcedony Geode (SiO2)
Granite
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
Rough Blue Sapphire
Corundum (Al2O3)
Amethyst (Chevron or Banded variety)
Silicon Dioxide with Iron impurities (SiO2)
Granite
Phaneritic Felsic Intrusive Igneous Rock
Weathered basaltic cobble
Basalt, likely amygdaloidal or vesicular basalt
Tumbled basalt (likely)
Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine
Red Sandstone
Arenite (Iron-rich)
Mica Schist with Garnet
Garnet-Mica Schist
Granite River Pebble
Granite
Chert Breccia
Brecciated Chert (Microcrystalline Silica, SiO2)
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Iron-rich vesicular rock, possibly slag or weathered basalt
Identification uncertain; likely ferruginous basalt/ironstone, with possible anthropogenic iron slag
Granite
Felsic intrusive igneous rock
Amethyst
Silicon Dioxide (SiO2)
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Quartz-encrusted Matrix
Silicon Dioxide (SiO2) with Ferruginous Sandstone