Man-made Blank Ammunition (Brass)
CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)
Anticrystalline / Synthetic Alloy
Category
Synthetic (Not A Natural Rock)
Browse synthetic (not a natural rock) specimens identified by the Rock Identifier community.
Learn about Synthetic (Not A Natural Rock) in the encyclopedia
View all →
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Amethyst
Amethyst (Silica mineral, SiO2)
mineral
Moldavite
Tektite (Natural Silicate Glass)
gemstone
Tumbled citrine or iron-stained quartz
Quartz (SiO₂), likely iron-oxide-stained or natural citrine
mineral
Fossilized tooth or tooth fragment
Indeterminate vertebrate tooth; likely mammalian, mineralized hydroxyapatite
fossil
River Cobble (Sandstone / Greywacke)
Sedimentary Rock (predominantly Quartz, Feldspar, Lithic fragments)
sedimentary
Sandstone (River Cobble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Jasper and Chalcedony Nodule
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Banded Gneiss River Pebble
Gneiss
metamorphic
Amethyst
Crystalline Quartz (SiO2 with iron impurities)
gemstone
Dyed Blue Agate
Silicon Dioxide (SiO2) with artificial pigment
mineral
Pickled Dragon Eggs (Fictional Interpretation: Purple Agate or Amethyst Geodes)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Mixed rock and mineral gravel
Predominantly granite/granodiorite, basaltic rocks, quartz, and possible gneiss; exact identification is uncertain from the image
igneous
Grey Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with Fe2O3)
sedimentary
Pink Dyed Agate
Silicon Dioxide (SiO2) - Variety Agate
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Granite
Granite (phaneritic intrusive igneous rock consisting of quartz, feldspar, and mica)
igneous
Shale (with Iron Oxide staining)
Fissile Mudstone (primarily Quartz and Clay minerals)
sedimentary
Gneiss
Gneiss (foliated metamorphic rock)
metamorphic
Basalt
Basalt
igneous
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Tufa Rock and Tumbled Gemstones
Calcareous Tufa (Calcium Carbonate, CaCO3)
sedimentary
Tumbled porphyritic granite
Granite, primarily quartz, alkali feldspar, plagioclase, and biotite/hornblende
igneous
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
River Pebble (Quartz-rich)
Silicon Dioxide (SiO2) with impurities
sedimentary
Blue Dyed Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Granite
Granite (Felsic Plutonic Rock)
igneous
Granite
Phaneritic Plutonic Felsic Rock
igneous
Tumbled agate (likely Botswana or fortification agate)
Microcrystalline quartz, SiO₂ (chalcedony with banded impurities)
mineral
Sodalite
Sodalite (Na4Al3Si3O12Cl)
Mineral
Granite
Phaneritic intrusive felsic igneous rock
igneous
Banded Sandstone (Liesegang Rings)
Arenite with Liesegang rings (SiO2/Fe2O3)
sedimentary
Sandstone
Sedimentary Rock (Quartz Arenite)
sedimentary
Limonite (Ochreous Sandstone)
Hydrous ferric oxides (FeO(OH)qnH2O)
sedimentary
Slag
Ferrous Slag (Siliceous industrial waste)
Anthropogenic (Man-made industrial byproduct)
River Cobble (Quartzite or Gneiss)
Metamorphic crystalline rock (predominantly SiO2 based)
metamorphic
Swirled Agate Bead
Silicon Dioxide (SiO2)
mineral