Sea Glass
Amorphous Silica (SiO2) with various additives
Mineraloid (Anthropogenic)
Category
Igneous Or Sedimentary (Anthropogenic Modification)
Browse igneous or sedimentary (anthropogenic modification) specimens identified by the Rock Identifier community.
Learn about Igneous Or Sedimentary (Anthropogenic Modification) in the encyclopedia
View all →
Slag
Ferrous slag (by-product of iron smelting)
Mineraloid / Anthropogenic
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Polished banded metamorphic stone, likely gneiss or quartzite
Banded quartz–feldspar–mica rock; precise identification requires testing
metamorphic
Banded gneiss, possibly garnet-bearing
Foliated gneiss; predominantly quartz–feldspar–mica, with possible amphibole or garnet
metamorphic
Polished banded gneiss or schist pebble
Banded quartz–feldspar–mica gneiss (tentative)
metamorphic
Weathered iron-rich rock, possibly limonite-bearing basalt or ironstone
Undetermined; likely iron oxides/hydroxides (goethite–hematite–limonite) in a silicate host
mineral
Botryoidal Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Clear Quartz Geode
Crystalline Silicon Dioxide (SiO2)
mineral
River Cobble (Salt and Pepper Gneiss)
Gneiss (High-grade regional metamorphic rock)
metamorphic
Gneiss (Metamorphic Pebble)
Gneissic Metamorphic Rock
metamorphic
Crackle Agate / Dyed Quartz
SiO2 (Silicon Dioxide)
mineral
Gneiss
Gneiss
metamorphic
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Banded gneiss
Foliated, banded gneiss; typically composed of quartz and feldspar with mica or other dark minerals
metamorphic
Banded gneiss pebble
Gneiss, chiefly quartz–feldspar–mica; exact variety indeterminate from image
metamorphic
Rounded metamorphic cobble, likely gneiss or amphibolite
Banding-free biotite–quartz–feldspar gneiss or amphibolite; exact identification requires testing
metamorphic
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Gneiss
Gneiss
metamorphic
Asphalt fragment
Bituminous concrete
anthropogenic material
Paper (Cellulose)
Cellulose (C6H10O5)n
Organic (Anthropogenic)
Cullet (Slag Glass)
Amorphous Silica (SiO2) with various metal oxide colorants
mineraloid / anthropogenic
Slag (Industrial Glass Slag)
Amorphous Silica / Ferro-silicate Slag
mineraloid / anthropogenic
Gneiss (Pebble)
Gneiss
metamorphic
Biotite-bearing gneiss
Mica gneiss, composed mainly of quartz, feldspar, and biotite mica
metamorphic
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Slag (Industrial Byproduct)
Ferrous/Non-ferrous Silicate
igneous (artificial/anthropogenic)
Slag
Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)
igneous (artificial/anthropogenic)
Banded gneissic rock
Gneiss, likely quartz–feldspar–biotite gneiss
metamorphic
Banded metamorphic rock, likely gneiss
Biotite–quartz–feldspar gneiss, possibly amphibolite-bearing
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Gneiss
Gneiss
metamorphic
Gneiss
Gneiss
metamorphic
Banded Agate
Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Gneiss
Gneiss
metamorphic
Banded Gneiss
Gneiss (Metamorphic rock)
metamorphic
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Banded Gneiss
Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica)
metamorphic
Gneiss
Gneiss
metamorphic
Banded gneiss pebble
Biotite–quartz–feldspar gneiss (composition variable)
metamorphic
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic