Lightning Stone / Fulgurite-impregnated or Septarian-like Agate
Silicon dioxide (Quartz/Chalcedony) with host rock matrix
sedimentary
Category
Synthetic (Not A Natural Rock)
Browse synthetic (not a natural rock) specimens identified by the Rock Identifier community.
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Rutilated Quartz
Quartz (SiO2) with Rutile inclusions (TiO2)
Mineral
Sandstone Pebble with Mineral Encrustation
Quartz Sandstone with Calcite/Halite Crust
sedimentary
Shale
Shale (claystone/mudstone)
sedimentary
Sandstone (with vugs or solution cavities)
Arenite (primarily Quartz and Feldspar with CaCO3 or SiO2 cement)
sedimentary
Opalite (Man-made Glass)
Fused glass (typically made of dolomite and metal opacifiers)
Man-made Material / Glass
Shale
Argillite / Shale
sedimentary
Shale
Sedimentary Shale
sedimentary
Druzy Quartz on Matrix
Silicon Dioxide (SiO2) on host rock
mineral
Limonite (Iron Ore)
Hydrous ferric oxides (FeO(OH)·nH2O)
mineral
Mahogany Obsidian
Obsidian (Volcanic Glass) with Hematite or Magnetite inclusions, SiO2 (Silicon Dioxide)
igneous
Shale
Argillaceous Rock
sedimentary
Heart-shaped Limestone
Calcium Carbonate (CaCO3)
sedimentary
Seashell Fossil
Invertebrate Bivalve / Gastropod Fossil (Calcium Carbonate, CaCO3)
fossil
Sandstone (likely Arkosic)
Clastic Sedimentary Rock (primarily SiO2 with Feldspar)
sedimentary
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Slag Glass (Cullet)
Amorphous Silica (man-made), primarily SiO2 with trace metal oxides
Mineraloid / Synthetic Glass
Heart-shaped Quartz
Silicon Dioxide (SiO2)
mineral
Herkimer Diamond (Quartz Crystal)
Silicon Dioxide (SiO2)
mineral
Strawberry Quartz
Silicon Dioxide (SiO2) with inclusions of Goethite or Hematite
Mineral
Blue goldstone beads
Man-made aventurine glass (silica glass with metallic copper inclusions), not natural lapis lazuli
mineral
Grey River Pebble (Greywacke / Basalt)
Stream-rounded silicate rock pebble
sedimentary
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
sedimentary
Smoky Quartz and Chalcedony Geode Fragment
Silicon Dioxide (SiO2)
mineral
Blue Chalcedony (likely dyed Agate)
Silicon Dioxide (SiO₂)
mineral
Diamond
Carbon (C)
gemstone
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary
Vesicular Basalt (or Scoria)
Vesicular Basalt
igneous
Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
mineral
Concrete / Anthropogenic Conglomerate
Man-made composite material (Portland cement, aggregate, and water)
not a natural rock
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (primarily Quartz-rich)
sedimentary
Shale with Iron Staining
Fissile Argillaceous Sedimentary Rock
sedimentary
Limonite (Yellow Ochre)
FeO(OH)·nH2O (Hydrous iron(III) oxide-hydroxide mixture)
Mineral (Iron Ore)
Yellow Quartz (Citrine Quartz Pebble)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (Clastic Sedimentary Rock)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, FeO(OH)·nH2O)
mineral
Sandstone (Quartz-rich)
Arenite (primarily SiO2)
sedimentary