Chert (Basanite)
Chert (Microcrystalline SiO2)
sedimentary
Category
Organic Gemstone
Browse organic gemstone specimens identified by the Rock Identifier community.
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Glauconitic Sandstone
Glauconitic sandstone ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Fossilized Shark Tooth
Carcharocles or Otodus sp. (Micro-fossilized)
sedimentary
Pyrite (Fool's Gold) Cube
Iron Sulfide (FeS2)
mineral
Chert (Jasper)
Cryptocrystalline Silicon Dioxide (SiO2)
sedimentary
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
sedimentary
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
sedimentary
Flint (Chert)
Silicon Dioxide (SiO2)
sedimentary
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
mineral
Banded Chert / Jasper
Silicon Dioxide (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Fossiliferous Limestone
Calcite-rich Fossiliferous Limestone (CaCO3)
sedimentary
Dendritic Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
mineral
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
sedimentary
Amber
Succinite (fossilized tree resin)
mineraloid / sedimentary organic material
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
sedimentary
Amber
Succinite (specifically for Baltic amber); chemical formula approximately C10H16O
Mineraloid
Flint (chert), likely brown flint
Microcrystalline quartz/chalcedony (SiO₂)
sedimentary
Moss Agate
Chalcedony (SiO2 with inclusions)
mineral
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (Permineralized wood)
fossil
Amber
Succinite (Resin C10H16O)
mineral
Zebra Rock / Zebra Marble
Banded Limestone-Marble Transition
metamorphic
Amber
Succinite (Fossilized Tree Resin)
mineraloid
Amber
Succinite (fossilized resin)
mineral
Amber
Succinite (fossilized tree resin)
mineraloid
Amber
Succinite
Organic Mineral
Amber
Succinite (Formula: C10H16O)
Organic Mineraloid
Black Limestone with Calcite Veins
Limestone (Calcium Carbonate, CaCO3)
sedimentary
Amber (with potentially inclusions)
Succinite (Fossilized Tree Resin)
Mineraloid
Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
sedimentary
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
sedimentary
Cubic Zirconia (simulant) or Diamond
ZrO2 (Cubic Zirconia) or C (Diamond)
gemstone
Fossiliferous Rock (Invertebrate Fossil in Matrix)
Fossiliferous limestone or shaly matrix containing skeletal fossil remains
fossil
Limestone (or Sandstone)
Calcium Carbonate (CaCO3) / Silica (SiO2)
sedimentary
Sandstone (with Moss)
Quartz Arenite / Sandstone
sedimentary
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Limestone (Carved Statue)
Calcium Carbonate (CaCO3)
sedimentary
Poppy Jasper
Microcrystalline Quartz (SiO2) with mineral inclusions
sedimentary
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (primarily CaCO3)
sedimentary