Limestone
Calcium Carbonate (CaCO3)
Category
Browse man made material (anthropogenic 'mineraloid') specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
Sandstone (River Cobble)
Clastic sedimentary rock (primarily SiO2 with various lithic fragments)
Quartzite (Iron-stained)
Quartzite (SiO2 with iron oxides)
Scoria (Volcanic Rock)
Scoria (often basaltic scoria)
Red Jasper (beads)
Silicon Dioxide (SiO2) with iron inclusions
Laterite
Laterite (no specific mineral formula as it's a rock type)
Diamond
Diamond (C)
Diamond
Diamond (carbon allotrope), C (chemical formula)
Clear Quartz (Rock Crystal)
Quartz (SiO₂)
Quartz (likely Rose Quartz or Milky Quartz based on color)
Quartz (SiO2 - Silicon Dioxide)
Hypersthene (or Enstatite/Ferrosilite)
Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)
Granite (weathered/river-tumbled)
Granite (Plutonic Igneous Rock)
Granite
Granite (felsic intrusive igneous rock)
Rose Quartz
Rose Quartz (SiO₂)
Diamond
Carbon (C), specifically in an isometric crystal system.
Chalcedony (Common Opal/Chert variety)
Silicon Dioxide (SiO2)
Diamond
Diamond (pure carbon; C)
Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Pyrite
Pyrite (Iron Disulfide), FeS2
Yellow Jade (often Serpentine or Dolomite)
Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Fuchsite Quartzite
Fuchsite-bearing Quartzite
Calcite
Calcite (Calcium Carbonate, CaCO3)
Petrified Wood
Silicified wood, primarily composed of Quartz (SiO2)
Granite
Granite (a plutonic igneous rock)
Agate
Agate (a cryptocrystalline variety of Quartz, SiO₂)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Shale (possibly)
Shale (fine-grained clastic sedimentary rock)
Diamond
Diamond (pure carbon, C)
Quartz (in a rock matrix)
Quartz (SiO2)
Granite
Granite (a felsic intrusive igneous rock)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz
Silicon Dioxide (SiO2)
Basalt
Basalt (extrusive igneous rock)
Amazonite
KAlSi3O8 (Potassium Feldspar, variety of Microcline)
Sandstone
Arenite or Sandstone
Sugilite
Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Chrysoprase
Chrysoprase (a variety of Chalcedony, SiO₂)
Quartzite
Quartzite (primarily SiO2)
Quartz (likely a weathered/tumbled piece)
Quartz (SiO₂)