Milky Quartz (Water-Worn Cobble)
Silicon Dioxide (SiO2)
Category
Browse mineral (native element alloy) specimens identified by the Rock Identifier community.
Milky Quartz (Water-Worn Cobble)
Silicon Dioxide (SiO2)
Sandstone (likely Graywacke or Lithic Sandstone)
Arenite / Wacke (SiO2 based with lithic fragments)
Opalite
Synthetically produced glass (Silicon Dioxide with metallic inclusions)
Serpentine Schist with Quartz Vein
Serpentine Schist (a type of Metamorphic rock). The white band is likely Quartz (SiO2).
Slate
Slate (Foliated Metamorphic Rock)
Amygdaloidal Basalt
Amygdaloidal Basalt
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
Meteorite (Chondrite)
Stony Meteorite (Ordinary Chondrite)
Calcite
Calcite (CaCO3)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Bauxite (Concretionary)
Bauxite (Al(OH)3, AlO(OH))
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Metasedimentary or Igneous matrix
Milky Quartz Pebble with Chert
Silicon Dioxide (SiO2)
Quartz (Chert/Chunky Chalcedony)
Silicon Dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Natural Gemstone Cabochons (Ruby, Moonstone, Emerald, Citrine)
Ruby (Al2O3:Cr), Moonstone (KAlSi3O8), Emerald (Be3Al2(SiO3)6:Cr), Citrine (SiO2)
Dendritic Siltstone (or Mudstone)
Siltstone with Manganese Oxide dendrites
Quartz (Milky/Clear Variety)
Silicon Dioxide (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Mixed Quartz and Jasper Pebbles
Silicon Dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Potassium Feldspar (Orthoclase)
KAlSi3O8
Obsidian
Volcanic Glass (SiO2 rich)
Fluorite
Fluorite (Calcium Fluoride - CaF2)
Quartz Pebble
Silicon Dioxide (SiO2)
River Quartz Cobble
Silicon Dioxide (SiO2)
Labradorite (Larvikite variety)
Plagioclase Feldspar (Na,Ca)(Si,Al)4O8
Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Black Obsidian
Obsidian (Volcanic Glass)
Siltstone with iron staining
Siltstone (primarily SiO2 with FeO(OH) coatings)
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2
Glauconitic Sandstone
Greensand (Glauconite-bearing sandstone)
Limonite (Ironstone Concretion)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
River Rock (Greywacke/Sandstone)
Lithic Wacke
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Potassium Feldspar and Quartz
KAlSi3O8 (Potassium Feldspar) and SiO2 (Quartz)
Clear Quartz Crystal
Silicon Dioxide (SiO2)
Blue Sapphire (likely costume glass imitation)
Corundum (Al2O3) with iron/titanium impurities
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)