Quartz (pebble)
Quartz (SiO₂)
Category
Browse man made material (constructed) specimens identified by the Rock Identifier community.
Quartz (pebble)
Quartz (SiO₂)
Agate
Agate (Cryptocrystalline Variety of Quartz, SiO2)
Chert (or Flint)
Chert (microcrystalline or cryptocrystalline quartz, SiO2)
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Granite
Granite (Felsic intrusive igneous rock)
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Pyrite
Pyrite (Iron Disulfide), FeS2
Mookaite Jasper
Siliceous sedimentary rock (variety of Jasper/Chert)
Pebble
Clast (specifically a granule or small pebble)
Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Quartz (possibly milky quartz or quartz with inclusions)
SiO2 (Silicon Dioxide)
Fossil Coral
Fossilized Scleractinia or Tabulata (various genera/species)
Peridot (likely, given the color and bead form)
Olivine, variety Peridot (Mg,Fe)2SiO4
Clear Quartz (or Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Chalcedony or Chert/Jasper with secondary mineral staining
SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.
River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Calcite
Calcite (CaCO3)
Banded Chert
Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)
Amethyst Geode/Cluster
Quartz (SiO2) - variety Amethyst
Chert (varieties include Flint or Jasper)
Chert (cryptocrystalline quartz; SiO₂)
Chert
Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)
Conglomerate (Puddingstone)
Conglomerate (specifically, clastic sedimentary rock)
Bauxite Ore
Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)
Shale
Shale (fine-grained clastic sedimentary rock)
Agate
Agate (a variety of Chalcedony, SiO2)
Peridot
Olivine (specific variety: gem-quality forsterite), (Mg,Fe)2SiO4
Biotite Mica
K(Mg,Fe2+)3(Al,Fe3+)Si3O10(OH,F)2
Quartz (likely Milky Quartz)
Quartz (SiO₂ - Silicon Dioxide)
Ocean Jasper
Orbicular Jasper (variety of Chalcedony - SiO2)
Citrine Quartz
Quartz (SiO2) - specifically, a variety of macrocrystalline quartz
Quartz (likely Milky Quartz or Chalcedony)
Quartz (SiO2 - Silicon Dioxide)
Fuchsite Quartzite
Fuchsite-bearing Quartzite
Stainless Steel Spoon
Iron-Chromium Alloy (Fe + Cr + Ni)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
K2 Azurite Granite / K2 Stone
Granite (igneous rock) with Azurite inclusions (mineral)
Granite (tumbled pebble)
Granite (Plutonic Igneous Rock)
Quartz
Quartz (SiO₂)
Schist
Schist (various mineral compositions)
Micaceous Sandstone or Quartzite
Sandstone (lithified quartz grains, often with mica) or Quartzite (metamorphosed sandstone)
Cobalt Blue Sea Glass
Amorphous Silica Glass (SiO2 + CoO)
Sandstone
Arenite or Sandstone