Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Brachiopod Fossil (Spiriferid)
Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)
Green Moss Agate
Agate (Silicon Dioxide - SiO2 with inclusions of Manganese/Iron oxides)
Leopard Skin Jasper
Orbicular Rhyolite (Silicon Dioxide with various impurities)
Shungite
Shungite (carbon-rich Precambrian mineraloid)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide
Moss Agate
Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions
Amber
Succinite (Fossilized Tree Resin) - C10H16O
Sandstone
Quartz Sandstone (predominantly)
African Turquoise (Jasper)
Polychrome African Jasper (often marketed as 'African Turquoise' due to its color, but it is not true turquoise)
Blue Quartzite
Quartzite (primarily SiO2 with inclusions like Dumortierite or Magnesio-riebeckite)
Note: No specimen visible
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Pebble (likely Sandstone or Granitic Pebble)
Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)
Chert (Jasper)
Silicon Dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Fluorite in Matrix
Fluorite (CaF2) within a host rock matrix
Petoskey Stone
Hexagonaria percarinata (Fossilized Coral)
Pebble
Clast (specifically a granule or small pebble)
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Chert (often called Flint)
Silicon Dioxide (SiO2)
Chert (often called Flint or River Rock)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Blue Sapphire
Corundum (Al2O3)
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Lapis Lazuli
Lapis lazuli (a metamorphic rock primarily composed of Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Amber
Succinite (fossilized resin)
Quartz
Quartz (SiO₂)
Unakite (Tumbled)
Epidotized Granite
Sandstone (Weathered Cobble)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Sandstone (clastic sedimentary rock)
Mosasaur Tooth Fossil
Mosasaurid vertebrate fossil (Hydroxyapatite)
Mixed Tumbled Gemstones and River Rocks
Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Chert (Commonly known as Flint)
Microcrystalline Quartz (SiO2)
Basalt
Basalt (extrusive volcanic rock)
Dalmatian Stone
Peralkaline Quartz-Feldspar Rock
Red Jasper
Jasper (Silicon Dioxide) - SiO2
Graphite
Graphite (Native Carbon), Formula: C