Black Obsidian
Obsidian (Amorphous Silicon Dioxide)
igneous
Category
Man Made Byproduct (Non Geological)
Browse man made byproduct (non geological) specimens identified by the Rock Identifier community.
Learn about Man Made Byproduct (Non Geological) in the encyclopedia
View all →
Pink Quartzite
Quartzite (SiO2)
metamorphic
Snowflake Obsidian
Vitreous Volcanic Rock (Amorphous Silicate), SiO2
igneous
Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Rose Quartz
Silicon Dioxide with traces of titanium, iron, or manganese (SiO2)
mineral
Snowflake Obsidian
Obsidian with Cristobalite inclusions (70–75% SiO2)
igneous
Diamond (Cut Gemstone)
Natural Carbon (C)
gemstone
Lapis lazuli and green-blue chalcedony jewelry
Lapis lazuli: lazurite-bearing metamorphic rock, chiefly lazurite (Na₃Ca(Al₃Si₃O₁₂)S) with calcite and pyrite; second stone: likely chrysoprase or green-blue chalcedony (microcrystalline quartz, SiO₂)
gemstone
Obsidian
Volcanic glass (SiO2 + impurities)
igneous
Quartzite
Metamorphic Quartz Rock (SiO2)
metamorphic
Obsidian
Volcanic glass (SiO2 - Silicon dioxide predominant composition)
Igneous
Black Obsidian
Volcanic Glass (felsic)
igneous
Black Tourmaline (Schorl)
Sodium Iron Aluminum Borosilicate (NaFe2+3Al6(BO3)3Si6O18(OH)4)
mineral
Obsidian
Obsidian (Volcanic Glass)
igneous
Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Obsidian
Amorphous volcanic glass (70-75% SiO2)
igneous
Obsidian
Obsidian (Volcanic Glass, SiO2)
igneous
Shale
Shale (composition varies: primarily clay minerals and quartz)
sedimentary
Drill Core Sample
Cylindrical Rock Core (Specific mineralogy varies by extraction site)
Metamorphic (Likely Gneiss or Schist based on texture)
Obsidian Arrowhead
Volcanic Glass (predominantly SiO2)
igneous
Obsidian
Volcanic Glass (Amorphous SiO2-rich glass)
Igneous
Black Obsidian
Obsidian (Volcanic Glass)
igneous
Black obsidian (probable)
Volcanic glass; primarily SiO₂-rich rhyolitic composition
igneous
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
sedimentary
Quartzite Pebble
Metamorphic Quartzite
metamorphic
Black Obsidian
Obsidian (Volcanic glass), 70–75% SiO2
igneous
Grey Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Obsidian (Apache Tear)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
igneous
Pyrite
Iron Disulfide (FeS2)
Mineral
Chert (and/or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Limestone with Chert Nodule
Carbonate rock (CaCO3) with Microcrystalline Silicon Dioxide (SiO2) inclusion
sedimentary
Chert (Grey-Green Flint)
Microcrystalline silicon dioxide (SiO2)
sedimentary
Obsidian
Volcanic Glass (70-75% SiO2)
igneous
Polished Black Obsidian
Volcanic Glass (70-75% SiO2)
igneous
Conglomerate
Conglomerate (Sedimentary Clastic Rock)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Weathered agate or chalcedony nodule
Microcrystalline quartz (SiO₂), likely agate/chalcedony with iron-oxide staining
mineral
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Snowflake Obsidian
Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)
igneous
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Dyed or treated turquoise-like tumbled stone
Likely turquoise (CuAl₆(PO₄)₄(OH)₈·4H₂O), though blue-green magnesite or howlite imitation is possible
mineral
Obsidian Arrowhead
Obsidian (volcanic glass, SiO2 rich)
igneous