Sandstone (Flagstone)
Arenite (composed primarily of SiO2)
Category
Browse metamorphic or sedimentary depending on local grade specimens identified by the Rock Identifier community.
Sandstone (Flagstone)
Arenite (composed primarily of SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Orange Calcite
Calcium Carbonate (CaCO3)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Banded Iron Formation
Banded Iron Formation (BIF)
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Sapphire
Corundum (Al2O3)
Blue Sapphire (Synthetic or Man-made Glass Imitation)
Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic
Green Fluorite (likely synthetic or heat-treated for jewelry)
Calcium Fluoride (CaF2)
Smoky Quartz
Smoky Quartz (SiO2 - Silicon Dioxide with aluminum impurities)
Silver (Native Element)
Ag (Argentum)
Rainbow Moonstone
White Labradorite (formula: (Na,Ca)(Al,Si)4O8)
Anthracite Coal
Anthracite
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Quartz
Silicon Dioxide (SiO2)
Orthoclase Feldspar
Potassium aluminum silicate (KAlSi3O8)
Quartz with Pyrite
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
Yellow Quartz (Citrine/Gold Quartz)
Silicon Dioxide (SiO2)
Rose Quartz
Rose Quartz (SiO2)
Green Quartzite
Quartzite (SiO2)
Lapis Lazuli
Na8[Al6Si6O24]n(S,Cl,SO4,OH)2 (Lazurite and other associated minerals)
Shungite
Non-crystalline carbon (Fullerenes / Carbon-60)
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Porcelain (White Ceramic)
Mullite-bearing Vitrified Ceramic (Major phases: Mullite Al6Si2O13, Glassy Silica SiO2)
Lapis Lazuli
Lapis Lazuli (Aggregate primarily of Lazurite: (Na,Ca)8(AlSiO4)6(S,SO4,Cl,1-2) with Calcite and Pyrite)
Quartzite (Yellow/Orange variety)
Quartzite (composed primarily of Silica, SiO2)
Lapis Lazuli (polished cabochon/sphere)
Na8[Al6Si6O24]Sn with accessory minerals (Pyrite, Calcite)
Agate (translucent slice)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Porcelain Tile (Sandstone-look)
Man-made Ceramic (resembling Quartz-rich Sandstone)
Blue Sapphire
Corundum (Al2O3 with trace Titanium and Iron)
Limonite Concretion
Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O
Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
Fossilized Gastropod in Chert/Limestone
Internal mold of Gastropoda (Class) with CaCO3 or SiO2 mineral formula
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
Smoky Quartz
Silicon Dioxide (SiO2)
Blue Sapphire
Corundum (Al2O3)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Sunstone
Aventurine Feldspar (Plagioclase Feldspar with inclusions)
Nuummite
Nuummite (Ortho-amphibole rock, primarily Anthophyllite and Gedrite)