Polished agate or jasper cabochon
Cryptocrystalline quartz, SiO₂, possibly iron-rich jasper inclusions
gemstone
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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Amber (Rough Baltics/Beach Specimen)
Succinicum (Organic Gemstone - Fossilized Resin)
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
mineral
Chert with Calcite Veins
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) intrusions
sedimentary
Shark Tooth Fossil
Carcharodon / Otodus fossilized tooth (Calcium Phosphate / Hydroxyapatite)
fossil
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Amber
Succinates (Fossilized Tree Resin)
mineral
Chert (Nodule)
Chert (composition: SiO2)
sedimentary
Ironstone Concretion
Siderite / Hematite-bearing Sedimentary Rock
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Amber
Fossilized Tree Resin (C10H16O)
gemstone
Mammoth or Mastodon Tooth Fragment
Mammuthus / Mammut molar fragment
fossil
Polished green moss agate cabochon
Moss agate: microcrystalline quartz (SiO₂) with included chlorite/actinolite or iron-manganese minerals
mineral
Jasper
Silicon Dioxide (SiO2)
mineral
Quartz in Matrix (possibly Basalt or Siltstone host)
Silicon Dioxide (SiO2) in Host Rock
mineral
Rhodochrosite
Manganese Carbonate (MnCO3)
mineral
Fossilized Bone
Permineralized Vertebrate Bone
fossil
Chert (Jasper/Flint variant)
Microcrystalline quartz (SiO2)
sedimentary
Fuchsite
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
mineral
Banded Agate (specifically Carnelian Agate / Sardonyx)
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Jasper (Red-Brown)
Silicon Dioxide (SiO2) with Iron Oxide impurities
sedimentary
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz vein in dark host rock
Quartz (SiO₂), likely in basalt, gabbro, or altered mafic rock
mineral
Petrified Wood
Silicified wood (SiO2)
fossil
Dalmatian Stone
Peralkaline Quartz-Feldspar Porphyry with Arfvedsonite
igneous
Chert / River Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Blue Quartzite (Dyed)
Metamorphosed Quartz-rich Sandstone (SiO2 with organic dye)
metamorphic
Dendritic Agate (or Dendritic Opal)
SiO2 (for Agate), SiO2·nH2O (for Opal)
Mineral
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Sedimentary
Mammoth or Mastodon Tooth Fossil
Mammuthus / Mammut tooth
fossil
Shark Tooth Fossil
Vertebrate fossilized tooth (Chondrichthyes)
fossil
Fossil Shark Tooth
Selachimorpha (Chondrichthyes dental fossil)
sedimentary
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Red Sandstone with Reduction Spot
Quartzose Sandstone with a Leach/Reduction Spot
sedimentary
Amber
Succinite (C10H16O)
mineral
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
mineraloid
Tumbled Dalmatian jasper
Quartz-rich alkali rhyolite, commonly marketed as Dalmatian jasper; chiefly quartz, feldspar, and dark amphibole/biotite inclusions
igneous
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Shark Tooth Fossil
Carcharocles megalodon or similar fossilized shark tooth
fossil