Basalt
Extrusive mafic volcanic rock
Category
Browse granite specimens identified by the Rock Identifier community.
Basalt
Extrusive mafic volcanic rock
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Citrine (Heat-treated or Natural Quartz)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Greenstone
Metabasalt / Chlorite-Epidote Schist
Banded Chert (Agate)
Silicon Dioxide (SiO2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Sulfur
Native Sulfur (S8)
Silver (Native Element)
Ag (Argentum) - 90% Silver, 10% Copper alloy in specimen
Raw Corundum (Sapphire/Ruby variant)
Aluminum oxide (Al2O3)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Amethyst (Quartz)
Silicon Dioxide (SiO2) with Iron impurities
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Jasper)
Calcite
Calcite (Calcium Carbonate, CaCO3)
Clear Quartz
Silicon Dioxide (SiO2)
Green Aventurine
Aventurine Quartz (SiO2) with Fuchsite inclusions
Sandstone
Arenite (primarily SiO2)
Basalt
Basalt (composition predominately Plagioclase feldspar and Pyroxene)
Chert (often called Flint)
Microcrystalline Quartz (SiO2)
Quartz (Pink/Orange Variety)
Silicon Dioxide (SiO2)
Ironstone Concretion (Boji Stone/Moqui Marble type)
Goethite/Hematite-encrusted Sandstone Concretion
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (SiO2 based)
Milky Quartz
Silicon Dioxide (SiO2)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Ironstone Concretion
Limonitic/Hematitic Concretion
Gold
Native Gold (Au)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Black Obsidian
Volcanic Glass (SiO2)
Pink Quartz (Rose Quartz)
Silicon Dioxide (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxides)
Banded Chert / Flint
Silicon dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Quartz Geode
Silicon dioxide (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Glass / Silicon Dioxide (Man-made)
SiO2 (Amorphous Silicon Dioxide)
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium or Manganese
Chert Pebble (with Quartz Vein)
Chert (Cryptocrystalline Silica - SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)