Pyrite
Iron Sulfide (FeS2)
mineral
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
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Greenstone
Metabasalt
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Weathered brown stone, possibly basalt or iron-rich sedimentary rock
Indeterminate from photograph; likely fine-grained mafic rock (basalt) or ferruginous sandstone
igneous
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
igneous
Milky quartz fragment
Quartz (silicon dioxide, SiO₂)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Basalt (potential Glacial Erratic)
Extrusive Mafic Volcanic Rock (Basalt)
igneous
Dalmatian Jasper
Peralkaline rhyolite
igneous
Pink Granite
Phaneritic Plutonic Felsic Igneous Rock (Granite)
igneous
Weathered limestone or calcitic cave deposit
Calcite (CaCO₃), likely porous limestone/travertine
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Sand Grain (Silica/Quartz Grain)
Silicon Dioxide (SiO2)
sedimentary
Black Pebble (Basalt / Chert)
SiO2 (if Chert) or Mafic Igneous Rock (if Basalt)
igneous
Weathered chert or silicified limestone nodule
Microcrystalline quartz (SiO₂), possibly replacing limestone; exact identification requires testing
sedimentary
River Stone (River Pebble)
River Stone (Composition: primarily Quartzite, Chalcedony, and silicate minerals)
sedimentary
Quartz
Quartz (SiO2)
Mineral
Weathered iron-rich rock, possibly basalt or ironstone
Uncertain; likely weathered basalt (plagioclase–pyroxene) or hematite/goethite-bearing ironstone
igneous
Vein-filled Porphyry or Brecciated Jasper Pebble
Brecciated volcanic rock with quartz/calcite veins
igneous
Vesicular Basalt with Epidote/Amygdaloidal Basalt
Amygdaloidal Basalt (Mg, Fe)2SiO4 + Ca2(Al, Fe)3(SiO4)3(OH)
igneous
Orbicular Rhyolite (Rainforest Jasper)
Rhyolite containing Spherulites (SiO2 with impurities)
igneous
Dalmatian Jasper (Dalmatian Stone)
Dalmatian Stone (primarily Feldspar, Quartz, and Arfvedsonite/Tourmaline)
igneous
Quartz (Water-worn Pebbles)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2) within Sedimentary or Igneous host
mineral
Granite
Granite
igneous
Small rounded pebble, likely quartz-rich river stone
Indeterminate; likely quartz/chert-bearing lithic clast
sedimentary
Quartz Sand / Sandstone grains
Silicon Dioxide (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
sedimentary
River Agate (Chert/Chalcedony)
Cryptocrystalline Quartz (SiO2)
sedimentary
Basalt River Stone
Basalt
igneous
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Banded Carnelian Agate
Silicon Dioxide (SiO2)
sedimentary
Jasper with Epidote
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate Hydrate
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
River Rocks (Basalt and Sedimentary Stones)
Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock
igneous and sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Mixed River Pebbles (including Unakite and Jasper)
Polymineralic geological specimens
igneous and sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral