Tufa (Vesicular Limestone)
Tufa (form of Calcium Carbonate, CaCO3)
Category
Browse mineral like (anthropogenic) specimens identified by the Rock Identifier community.
Tufa (Vesicular Limestone)
Tufa (form of Calcium Carbonate, CaCO3)
Dark-colored Igneous Rock (likely Basalt or Diabase)
Basalt (extrusive igneous) or Diabase (intrusive igneous)
Red Sandstone
Arenite (primarily SiO2 with Fe2O3)
Diorite
Diorite (Intermediate intrusive igneous rock)
Banded Gneiss
Gneiss (High-grade metamorphic rock)
Blue Slag Glass
Amorphous Silica (Byproduct of smelting)
Pink Granite
Phaneritic plutonic rock (dominated by Alkali Feldspar)
Green Aventurine
Silicon Dioxide (Quartz) with Fuchsite inclusions (K(Al,Cr)2(AlSi3O10)(OH)2)
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)
Dendritic Agate
Silicon Dioxide (SiO2) with manganese/iron inclusions
Bismuth Crystal
Bismuth (Bi)
Astrophyllite
Potassium Sodium Iron Manganese Titanium Silicate Hydroxide (K3NaFe7Ti2Si8O24(OH)7)
Milky Quartz
Silicon Dioxide (SiO2)
Diamond (in jewelry setting)
Diamond (C - Pure Carbon)
Blue-dyed Quartz Druzy
Silicon Dioxide (SiO2) with artificial pigment
Limonite (Pseudomorph after Pyrite/Marcasite)
Hydrated Iron Oxide (FeO(OH)·nH2O)
Druzy Quartz on Host Rock
Silicon Dioxide (SiO2)
Quartz (Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Prehnite
Prehnite, Ca2Al(AlSi3O10)(OH)2
Chert (Iron-stained)
Silicon Dioxide (SiO2)
Sandstone (with secondary weathering/concretion)
Arenite (composed primarily of Quartz, SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Geode (Chert or Quartz Nodule)
Silicon Dioxide (SiO2)
Gneiss
Gneiss
Obsidian
Volcanic glass (SiO2 - Silicon dioxide predominant composition)
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
Obsidian
Volcanic glass (high silica volcanic rock)
Gneiss (specifically Biotite Gneiss)
Gneiss (high-grade metamorphic rock primarily composed of Silicates)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Garnet Schist
Almandine Garnet Schist
Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Sandstone (Quartzose Sandstone Pebble)
Arenite (primarily SiO2)
Bumblebee Jasper
Calcite-bearing Volcanic Tuff containing Sulfur and Arsenic (Orpiment/Realgar)
Diorite
Phaneritic intermediate plutonic rock
Ruby in Kyanite
Corundum in Disthene (Al2SiO5 + Al2O3)
Milky Quartz with Chlorite/Moss Infusions
Silicon Dioxide (SiO2)
Granitic Pegmatite
Granite Pegmatite (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Muscovite)