Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Category
Synthetic Glass (Often Categorized As A Simulated Mineral)
Browse synthetic glass (often categorized as a simulated mineral) specimens identified by the Rock Identifier community.
Pyrite
Iron Pyrite (FeS2)
Mineral
Chert (and/or Siltstone River Pebble)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Mineral
Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
mineral
Banded Quartzite River Pebble
Metamorphosed Quartz-rich Sandstone (SiO2)
metamorphic
Limonite/Goethite Nodule
Iron Oxyhydroxide (primarily FeO(OH)·nH2O)
mineral
Sandstone Geode (Ironstone Concretion)
Arenite with Limonite/Hematite matrix (SiO2 with Fe-oxides)
sedimentary
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Sandy Ironstone
Ferruginous Sandstone
sedimentary
Chrysocolla
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4 nH2O
mineral
Dyed Howlite (often sold as 'Turquenite')
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Obsidian
Volcanic Glass (70-75% SiO2)
igneous
Chert (Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Jasper (likely Lake Superior Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary (silica-rich mineral variety)
Chalcedony
Chalcedony (SiO₂)
Mineral
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Rutile in Quartz (Rutilated Quartz)
SiO2 with TiO2 inclusions
Mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble
Quartzite (predominantly Silicon Dioxide - SiO2)
metamorphic
Chert (Flint)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Quartzite
Metamorphosed Sandstone (SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Sedimentary Rock
Turquoise and Hematite
CuAl6(PO4)4(OH)8·4H2O (Turquoise) and Fe2O3 (Hematite)
mineral
Aventurine
Silicon Dioxide (SiO2 with inclusions of Fuchsite mica)
mineral
Yellow Ochre / Limonite
Limonite (inter-mixed iron oxides and hydroxides, primarily FeO(OH)·nH2O)
mineral
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Milky Quartz with inclusions
Quartz (Silicon Dioxide, SiO2)
mineral
Obsidian
Volcanic Glass (SiO2)
igneous
Obsidian
Volcanic glass (high silica SiO2)
igneous
Aventurine Quartz
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
mineral
Obsidian
Obsidian (volcanic glass), predominantly Silicon Dioxide (SiO2)
igneous
Moqui Marble (Concretion)
Iron Oxide Concretion (Hematite/Goethite)
sedimentary
Native Copper
Native Copper (Cu)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Obsidian
Obsidian (Volcanic Glass, primarily SiO2)
igneous
Onyx Marble (also commonly called Onyx)
Calcite (CaCO3), often with other mineral impurities
Sedimentary Rock (specifically a type of Travertine)
Quartz (likely Milky Quartz)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
sedimentary
Green Aventurine
Silicon Dioxide (Quartz) with inclusions of Fuchsite mica (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic