Tumbled brown agate (likely moss or plume agate)
Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide and possibly mineral inclusions
gemstone
Category
Mineral And Organic Gemstone
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
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Tufa Rock and Tumbled Gemstones
Calcareous Tufa (Calcium Carbonate, CaCO3)
sedimentary
Precious Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
gemstone
Precious Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Mineral (Organic Gemstone)
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
fossil
Yellow amber beads
Amber (fossilized tree resin; organic mineraloid, not a true mineral)
gemstone
Amber (polished piece)
Fossilized tree resin; amber is an organic mineraloid, not a true mineral
gemstone
Amber
Fossilized plant resin; primarily organic terpenoid compounds (not a mineral)
gemstone
Amber (Rough)
Succinite (Resinite)
gemstone
Tumbled moss agate (likely)
Chalcedony, microcrystalline quartz (SiO₂), with iron/manganese inclusions
gemstone
Red Coral
Corallium rubrum
mineral
Amethyst, Aquamarine, and Pearl Ring
SiO2 (Amethyst), Be3Al2Si6O18 (Aquamarine), CaCO3 (Pearl)
gemstone
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
mineral
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
mineral
Pearl necklace
Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)
gemstone
Amber with inclusion
Amber (Fossilized Tree Resin)
mineral
Amber
Fossilized tree resin; chiefly organic terpenoid resin (not a mineral)
gemstone
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Moss Agate
Chalcedony (Silicon Dioxide - SiO2) with inclusions
Mineral
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin, CaCO3
gemstone
Polished plume agate
Chalcedony (microcrystalline SiO₂) with iron-oxide inclusions
mineral
Fluorite
Fluorite (CaF2)
mineral
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
metamorphic
Amber (Dark/Black Variety)
Succinite (Resinite), C10H16O
mineral
Pearl jewelry
Pearl (biogenic calcium carbonate, primarily aragonite, CaCO₃)
gemstone
Fossiliferous Limestone
Fossiliferous Limestone
sedimentary
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineral
Amber
Fossilized Tree Resin (Generic formula roughly C10H16O)
mineral
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Amber (Copal)
Organic gemstone, fossilized tree resin (often immature amber or copal)
Mineral
Amber
Succinite (Fossilized Tree Resin)
gemstone
Chalcedony (Common Agate)
Silicon Dioxide (SiO2)
mineral
Agate (Moss or Green Agate)
Silicon Dioxide (SiO2)
mineral
Pearl
Organic Mineraloid (CaCO3 + Conchiolin)
mineral
Pearl
Calcium carbonate (Aragonite/Calcite) - CaCO3
gemstone
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Amber
Succinite (with formula approximately C10H16O)
Organic mineraloid
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Amber
Succinite (fossilized resin)
mineral
Jasper (Brown Iron-Rich Variety)
Silicon Dioxide (SiO2) with Fe2O3 (Iron Oxide/Crystalline Quartz)
sedimentary
Petrified Wood (Silicified Wood)
Silicified fossil wood (SiO2)
metamorphic