Quartz pebble
Silicon dioxide (SiO2)
mineral
Category
Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material) in the encyclopedia
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Chert (Cherty Flint/Jasper variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Quartz-bearing Pegmatite with Metallic Sulfides
Pegmatite / Quartz-Feldspar Matrix with Pyrite and Mica
igneous
Petrified Wood
Silicified Wood (SiO2)
fossil
Possible weathered metal-rich rock or slag fragment
Uncertain; possibly iron-oxide-rich breccia or industrial slag
mineral
Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Chert (specifically Yellow/Honey Jasper variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chrysocolla (with Malachite / Secondary Copper Minerals)
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O
mineral
Concrete
Anthropogenic Conglomerate
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
mineral
Petrified Wood Fragment
Silicified Wood (SiO2)
fossil
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Amber (and Citrine Quartz)
Succinite (Amber) and Silicon Dioxide (SiO2)
Organic Mineraloid and Mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Mineral (Variety of Chalcedony)
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Mother of Pearl (Nacre)
Aragonite (CaCO3) with Organic Matrix
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Polished green aventurine (likely)
Quartzite dominated by quartz (SiO₂), commonly containing fuchsite mica
mineral
Yellow quartz, possibly citrine
Quartz (SiO₂), yellow variety likely citrine; may also be iron-stained quartz
mineral
Peridot (Olivine)
Olivine (Magnesium Iron Silicate), (Mg,Fe)2SiO4
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Amethyst-bearing quartz cluster
Quartz, SiO₂; purple coloration from irradiation and trace iron
mineral
Shale
Shale (clastic sedimentary rock)
Sedimentary
Sandstone
Arenite (primary component SiO2)
sedimentary
Potassium-Rich Silicate Clay (inferred from biological context)
Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)
mineral
Basalt (River Rock/Cobble)
Basalt (no specific mineral formula as it's a rock)
Igneous
Diamond (as set in a metal alloy ring)
Diamond (Pure Carbon, C)
mineral
Possibly tumbled dark stone or mineral specimen
Indeterminate from image; possibly black tourmaline, basalt, or another dark silicate
mineral
Goldstone (Synthetic Aventurescence Glass)
Cuprous Aventurescent Glass (Silicon Dioxide with Copper inclusions)
mineraloid / man-made material
Sandstone with Algae Growth
Arenite with Chlorophyta/Lichen
sedimentary
Amber
Fossilized tree resin (not a true mineral as it is organic and amorphous); Chemical formula is highly variable, but often approximated as C10H16O.
Mineral
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclasts
sedimentary
Quartz (Milky or White Quartz)
Silicon Dioxide (SiO2)
mineral
Fossilized Shark Tooth (Eroded)
Carcharodon sp. or Otodus sp. fragment (likely)
fossil
Sand Tiger Shark Tooth (Fossil)
Carcharias taurus (fossilized dentin/enameloid)
fossil