Polished amber-like agate or jasper carving
Likely chalcedony (microcrystalline SiO₂), possibly iron-stained carnelian/jasper; exact identification requires testing
gemstone
Category
Organic Gemstone (Not A Rock)
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
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Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
sedimentary
Ruby in Zoisite
Anyolite (composite of Corundum and Zoisite)
metamorphic
Fancy Jasper
Jasper (Cryptocrystalline Quartz, SiO2)
sedimentary
Biological Bone (Patella/Knee)
Patella (part of the Human Skeletal System)
Organic Structure (Not a Rock)
Pearl oyster shell with cultured pearls
Mollusk shell (likely Pinctada spp.) containing aragonite pearls, CaCO₃
gemstone
Chert (Jasper/Agate)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Chert (SiO2)
sedimentary
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
mineral
Chert (Flint)
Chert (Cryptocrystalline Silicon Dioxide, SiO2)
sedimentary
Chert / Jasper / Agate (Chalcedony Group)
Microcrystalline Quartz (SiO2)
sedimentary
Shark Tooth Fossil
Vertebrate fossilized tooth
fossil
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Turquoise cabochon pendant
Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Fossilized Nut / Coprolite / Concretion
Trace Fossil / Permineralized Plant Material
fossil
Silty Shale or Mudstone
Siltstone/Mudstone (Clastic Sedimentary Rock)
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclastic Inclusions
sedimentary
Chert (variant Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Concretion
Septarian or Siderite Concretion
sedimentary
Chert (Flint/Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Tumbled brown chalcedony or quartzite pebble
Microcrystalline quartz (SiO₂), likely chalcedony; exact identification requires testing
mineral
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Shungite
Non-crystalline carbon (similar to anthracite coal or meta-anthracite)
metamorphic
Fossiliferous Limestone
Fossiliferous Limestone (Sedimentary Rock)
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
mineral
Polished amber-colored translucent stone, likely citrine or yellow chalcedony
Most consistent with quartz (SiO₂), potentially citrine; translucent yellow chalcedony is another possibility
mineral
Chert (Flint)
Microcrystalline Opaline Silica (SiO2)
sedimentary
Bivalve Fossil in Sedimentary Matrix
Fossiliferous Mudstone (Class: Bivalvia)
sedimentary
Chert (Black Chert or Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2) / Microcrystalline Quartz
sedimentary
Fossiliferous Limestone
Sedimentary rock containing Indeterminate Fossil remains (likely Crinoid stem or Bryozoan fragment)
fossil
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
sedimentary
Chert Concretion (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Flint Pebble)
Microcrystalline quartz (SiO2)
sedimentary
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
sedimentary
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Quartz Variety)
Chert (Silicon Dioxide, SiO2)
sedimentary
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Agatized Fossil Coral
Agatized Anthozoa
fossil
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Crushed Limestone
Sedimentary Calcite/Dolomite Rock (CaCO3)
sedimentary