Weathered quartz-rich pebble
Milky quartz, SiO₂, possibly quartzite or quartz-veined rock
mineral
Category
Rock
Browse rock specimens identified by the Rock Identifier community.
Small polished or naturally worn stone, possibly quartz-bearing rock
Indeterminate from the blurred image; likely quartz (SiO₂) or a pale feldspar-rich fragment
mineral
Quartz Druzy (Geode Fragment)
Silicon Dioxide (SiO2)
mineral
Snakeskin Jasper
Microcrystalline Quartz (SiO2) with iron inclusions
sedimentary
Agate (Common Chalcedony)
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Rock Crystal
Quartz (SiO2)
mineral
Quartzite
Quartzite, composed predominantly of quartz (SiO₂)
metamorphic
Greenstone, likely altered basalt (possibly serpentinite)
Metabasalt/greenschist; commonly chlorite–actinolite–epidote ± serpentine
metamorphic
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock
mineral
Quartz Pebble (Geode Fragment / Druzy Cavity)
Silicon Dioxide (SiO2)
mineral
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Pebble
Lithified rock fragment
sedimentary
Sandstone or Quartzite pebble
Sandstone (Quartz arenite) or Quartzite
sedimentary or metamorphic
River Cobble (Basalt or Sandstone)
Weathered Basalt or Fine-Grained Sandstone
igneous
Mixed River Pebbles (including Unakite and Jasper)
Polymineralic geological specimens
igneous and sedimentary
Greenstone (likely metamorphosed mafic rock)
Probable chlorite–actinolite–epidote-rich metabasalt; exact identification requires testing
metamorphic
Weathered quartz-rich pebble, possibly granite or pegmatite
Quartz (SiO₂) with probable feldspar and minor mica/iron-oxide inclusions
igneous
Peridotite
Ultramafic intrusive igneous rock
igneous
Quartz Pebble (with Iron Staining)
Crystalline Silicon Dioxide (SiO2)
mineral
Schist
Schist (metamorphic rock)
metamorphic
Pahoehoe Basalt
Extrusive mafic volcanic rock
igneous
Banded metamorphic rock, likely gneiss or metasedimentary slate
Quartz–feldspar–mica gneiss (tentative), possibly containing iron-oxide veins
metamorphic
Granodiorite or Diorite
Granodiorite / Diorite
igneous
Shale
Clastic Sedimentary Rock
sedimentary
Pumice
Pumice (Volcanic Rock)
igneous
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
White Topaz
Aluminum Silicate Fluoride Hydroxide; Al2SiO4(F,OH)2
mineral
Sandstone
Clastic sedimentary rock
sedimentary
Layered sandstone
Quartz-rich sandstone, likely arkosic or lithic sandstone
sedimentary
Weathered granitic rock
Granite, likely quartz–feldspar–mica aggregate
igneous
Agate
Silicon dioxide (chalcedony), SiO2
sedimentary
Fossilized Shark Tooth
Chondrichthyes teeth
fossil
Ammonite Fossil
Subclass Ammonoidea
fossil
Agate
Silicon dioxide (Chalcedony), SiO2
sedimentary
Agate
Silicon dioxide (SiO2)
sedimentary
Agate
Silicon Dioxide (SiO2)
sedimentary
Malachite on Quartz
Cu2CO3(OH)2 / SiO2
mineral
Mixed Tumbled Gemstones and Minerals
Various silicate and oxide minerals
mineral
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Porphyritic Basalt (River Rock)
Porphyritic Basalt
igneous
Rock Crystal
Quartz (SiO2)
mineral