Pumice
Pumice (volcanic rock)
Igneous
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
Learn about Amorphous Solid in the encyclopedia
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Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Sedimentary Rock
Smoky Quartz
SiO2 (Silicon Dioxide)
Mineral
Blue slag glass or dyed glass-like industrial material
Amorphous silicate glass; likely copper-bearing blue slag, but possibly colored man-made glass
mineral
Tektite (likely indochinite)
Natural silica-rich impact glass; predominantly amorphous SiO₂ with aluminum, iron, magnesium, calcium, and sodium
mineral
Limonite (Iron Ore)
Hydrous Iron Oxide (goethite, lepidocrocite)
Mineral
Dark Igneous Rock (Likely Basalt or Diabase)
Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.
Igneous
Banded Iron Formation (BIF)
Banded Iron Formation
Sedimentary
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Mineral
Scoria (Lava Rock)
Scoria
igneous
Red Scoria
Scoria (Vesicular Basalt/Andesite)
igneous
Scoria (Lava Rock)
Scoria
igneous
Vesicular Basalt (Scoria)
Mafic Igneous Volcanic Rock
igneous
Vesicular Basalt
Basalt (Extrusive Igneous Rock)
igneous
Scoria (Basaltic)
Vesicular Basalt
igneous
Scoria
Scoria (Vesicular Basaltic Rock)
igneous
Crushed Stone (Basalt/Gabbro)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Vesicular Basalt (Lava Rock)
Scoriaceous Basalt
igneous
Vesicular Basalt (or Scoria)
Basalt (Aphanitic-Vesicular Mafic Igneous Rock)
igneous
Vesicular Basalt
Basalt with vesicular texture
igneous
Scoria
Scoria (Vesicular Basalt/Andesite)
igneous
Scoria (Lava Rock)
Scoria (Extrusive Igneous Rock)
igneous
Scoria
Vesicular Basalt / Scoria
igneous
Pumice
Pumice (a highly vesicular volcanic rock)
igneous
Pumice
Pumice (a highly vesicular volcanic rock)
igneous
Pumice
Pumice (Highly vesicular felsic extrusive igneous rock; primarily SiO2)
igneous
Tumbled blue-gray stone, likely quartzite or fine-grained basalt
Provisional identification: quartzite (mostly quartz, SiO₂) or basalt (plagioclase–pyroxene); image alone cannot distinguish reliably
igneous
Wishing Stone (Graywacke with Quartz Vein)
Graywacke (immature sandstone) with a SiO2 (Quartz) intrusion
sedimentary
Scoria (Lava Rock)
Scoria (Extrusive Igneous Rock / Mafic Silicates)
igneous
Basalt (Vesicular)
Vesicular Basalt
Igneous
Dyed Howlite (often sold as Turquenite)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Satin Spar (often sold as Selenite)
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
mineral
Tumbled banded calcite (often sold as “onyx” or green onyx)
Calcite, CaCO₃; commonly banded cave/travertine calcite
mineral
Banded Calcite (often sold as Onyx or Mexican Onyx)
Calcite (CaCO3)
sedimentary
Banded Calcite (often sold as "Peaches and Cream" or "Orange Calcite")
Calcium Carbonate (CaCO3)
mineral
Satin Spar (often sold as Selenite)
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
mineral
Blue-dyed magnesite beads (often sold as “turquoise howlite”)
Magnesite, MgCO₃; commonly dyed blue and possibly marketed as dyed howlite, Ca₂B₅SiO₉(OH)₅
mineral
Granite
Intrusive Igneous Rock
igneous
Granite
Intrusive Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)
igneous
Granite Boulder
Intrusive Igneous Rock
igneous
Granite Pebble
Intrusive Igneous Rock (Quartz, Feldspar, Mica)
igneous
Granite
Intrusive Igneous Rock
igneous