Gneiss
Gneiss
metamorphic
Category
Man Made (Synthetic Rock)
Browse man made (synthetic rock) specimens identified by the Rock Identifier community.
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Gabbro (or Basalt Pebble)
Mafic Intrusive/Extrusive Igneous Rock
igneous
Basalt
Basalt
igneous
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sedimentary or Metamorphic
Sandstone (Glacial Cobble)
Arenite / Sedimentary Rock (primarily SiO2)
sedimentary
Quartzite Cobble
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Vesicular Basalt with Epidote
Vesicular Basalt (Mg, Fe)2SiO4 with Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Quartz Geode
Silicon dioxide (SiO2)
sedimentary
Ulexite
NaCaB5O6(OH)6·5H2O
mineral
Basalt
Extrusive Igneous Rock
igneous
Shale
Shale (clastic sedimentary rock composed of silt and clay-sized particles)
sedimentary
Dalmatian Jasper / Dalmatian Stone
Peralkaline Rock (Silicon Dioxide with Amphibole inclusions)
igneous
Basalt
Aphanitic Mafic Igneous Rock
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4
metamorphic
Sandstone (Ferruginous)
Arenite with Iron Oxide (Limonite/Hematite) coating
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
sedimentary
Veined Pebble (likely a Quartz-Veined Pebble)
Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)
Sedimentary Rock (possibly conglomerate or breccia with a quartz vein)
Quartzite River Rock
Quartzite (primarily SiO2)
metamorphic
Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Metamorphic, likely Sedimentary with Quartz veins
Quartz Druzy (on Matrix)
Silicon Dioxide (SiO2)
mineral
Pink Granite
Phaneritic Felsic Igneous Rock (Granite, rich in Potassium Feldspar)
igneous
Basalt with Quartz Veins
Mafic Igneous Rock (primarily Plagioclase and Pyroxene) with SiO2 inclusions
igneous
Sandstone
Sandstone (clastic sedimentary rock)
Rock
Scoria
Scoria
Igneous
Red jasper in gray host rock (likely hematite-stained quartzite or rhyolite)
Jasper: microcrystalline quartz (SiO₂), with iron-oxide coloration; exact host uncertain from image
mineral
Quartz Crystal Cluster on Matrix
Silicon Dioxide (SiO2)
mineral
Agate
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Agate (specifically a Yellow/Honey Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Quartz Crystal on Matrix
Silicon Dioxide (SiO2)
mineral
Basalt with Quartz Vein
Extrusive Igneous Rock / Volcanic Rock
igneous
Yellow Chert or Jasper
Microcrystalline Quartz (SiO2)
sedimentary
River Pebble (Quartz/Jasper)
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Fossiliferous Chert with Brachiopod Impression
Chert (SiO2) containing Brachiopoda fossil remains
sedimentary
Mixed Rock and Mineral Collection
Various geological specimens
igneous, sedimentary, and metamorphic
Druzy Quartz on Matrix (likely Limestone or Sandstone)
Silicon Dioxide (SiO2) with various trace impurities
Mineral on Sedimentary Rock
Unakite
Epidotized Granite
metamorphic
Sandstone
Arenite (SiO2 dominant)
sedimentary
Quartz-veined Mudstone or Argillite
SiO2 (Quartz) in Siltstone/Mudstone matrix
sedimentary