Gabbro
Plutonic mafic rock
Category
Browse synthetic material (not a rock or mineral) specimens identified by the Rock Identifier community.
Gabbro
Plutonic mafic rock
Devil's Toenail
Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Brick
Fired clay or Ceramic material (no specific mineralogical scientific name as it's a composite)
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
Chert (Flint)
Chert (SiO2)
Greenstone / Epidosite
Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)
Conglomerate
Conglomerate (clastic sedimentary rock)
Dacite
Dacite (Intermediate volcanic rock)
Granite
Phaneritic Plutonic Igneous Rock
Jasper / Chert (River Pebble)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
River Quartzite (River Rock)
Quartzite (SiO2)
Chert (Tan/Grey variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Jasper
Silicon dioxide (SiO2)
Chert (Commonly known as Flint)
Microcrystalline Quartz (SiO2)
Flower Jasper
Agatized Fossil Coral / Chalcedony (SiO2)
Banded Chert (River Stone)
Silicon Dioxide (SiO2)
Chert (specifically a weathered Chert nodule or fragment)
Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)
Diorite (with Iron Staining)
Phaneritic Intermediate Igneous Rock
Quartzite
Quartzite (SiO2)
Conglomerate (River Rock)
Clastic sedimentary rock (primarily SiO2)
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Chert (potentially Flint or Mudstone)
Microcrystalline Quartz (SiO2)
Diorite
Phaneritic Intermediate Plutonic Rock (Diorite)
Nuummite
Nuummite (Orthoamphibole rock / Anthophyllite-Gedrite blend)
Chert (specifically Gray Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Decomposed Granite
Grano-diorite/Granite-residuum (SiO2 primary)
Greenschist
Greenschist facies rock (containing chlorite, actinolite, albite, and epidote)
Petrified Wood
Silicified Wood (SiO2)
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Yellow/Tan)
Microcrystalline Quartz (SiO2)
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Sandstone (Red Flagstone)
Clastic sedimentary rock (primarily Quartz - SiO2)
Breccia
Breccia (Clastic Sedimentary Rock)
Basalt
Africite (Mafic Igneous Rock)
Basalt
Extrusive mafic igneous rock
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
Granite
Granite (a common type of Felsic Intrusive Igneous Rock)
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
Quartzite (Iron-stained)
Quartzite (SiO2 with Fe-oxides)