Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Category
Browse sedimentary like (industrial composite) specimens identified by the Rock Identifier community.
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Chalcedony (specifically Common Opal or Agate variant)
Silicon Dioxide (SiO2)
Chert (specifically Gray Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Chert (specifically Red Chert/Jasper nodule)
Microcrystalline Quartz (SiO2)
Chert (Green variety)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Anthracite Coal
Anthracite (C)
Slag Glass (Cullet)
Amorphous Silica / Glass residue
Anthracite Coal
Anthracite (Carbon rank grade)
Chert (Red Jasper)
Microcrystalline Quartz (SiO2)
Coal (Anthracite/Bituminous)
Carbo fossilium (primarily Carbon)
Anthracite Coal
Anthracite (Carbon-rich Sedimentary Rock)
Chert (Arrowhead Shard)
Microcrystalline silica (SiO2)
Chert (specifically Zebra Chert/Flint)
Silicon Dioxide (SiO2)
Diamond (or diamond simulant)
C
Weathered quartz-rich stone, possibly fossiliferous limestone
Indeterminate; likely calcite-rich limestone (CaCO₃) or weathered quartz-bearing rock
Orbicular jasper (orbicular chert), likely ocean jasper
Silicified microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and/or clay-rich orbicules
Milky Quartz / Quartz Geode Fragment
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2) within a sedimentary or volcanic shell
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 - Muscovite component)
Anthracite Coal
Anthracite (Carbon-based sedimentary-metamorphic rock)
Tumbled amber-colored chalcedony or jasper
Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper
Banded Siltstone Pebble
Siltstone (primarily SiO2, Al2O3, Fe2O3)
Sandstone Chert/Quartzite
Silicon Dioxide (SiO2) - Sedimentary Sandstone / Orthoquartzite
Garnet
Garnet group [X3Y2(SiO4)3]
Chert (Yellow Jasper/Flint pebble)
Microcrystalline Quartz (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Bauxite
Bauxite (mixture of Hydrous Aluminum Oxides)
Garnet Schist
Almandine Garnet in Schist (X3Al2(SiO4)3)
Quartz (Peach/Orange variety)
Silicon Dioxide (SiO2)
Magnetite Sand (Black Sand)
Magnetite (Fe3O4)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Magnetite / Iron Ore
Magnetite (Fe3O4)
Magnetite / Ironstone
Iron(II,III) oxide (Fe3O4)
Schist
Mica Schist
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (and Chalcedony/Agate mixture)
Microcrystalline Quartz (SiO2)
Chalk (Sedimentary Pebble)
Calcium Carbonate (CaCO3) - Biogenic Limestone
Chert (Nodule)
Chert (Silica, SiO2)
Greenstone / Graywacke
Lithic Sandstone (Graywacke)