Tufa Rock and Tumbled Gemstones
Calcareous Tufa (Calcium Carbonate, CaCO3)
sedimentary
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
Succinite (fossilized resin)
mineral
Bauxite
Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))
sedimentary
Fossil gastropod shell
Fossilized marine gastropod; exact genus/species requires locality and examination
fossil
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Amber (Copal)
Succinite (fossilized tree resin)
mineral
Amber
Succinite (fossilized resin)
mineral
Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Bloodstone (Heliotrope)
Cryptocrystalline Quartz (SiO2 with iron oxide inclusions)
mineral
Pearl
Aragonite (CaCO3 with conchiolin)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Chert Pebble (Beach Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Pearl
Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)
mineral
Amber
Succinite (C10H16O)
Mineraloid (Organic)
Beads (likely glass or man-made material)
N/A (artificial material)
Man-made material, not a natural rock or mineral specimen
Pearl (Biogenic Mineraloid)
Calcium carbonate (Aragonite) and Conchiolin, CaCO3
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Bloodstone (Heliotrope)
Cryptocrystalline Quartz (SiO2) with inclusions of Iron Oxide/Hematite
mineral
Pearl
Organic Mineral (CaCO3 with conchiolin)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3 with Carotenoid pigments)
Mineraloid (Organic Gemstone)
Quartz (Milky Quartz / Quartzite)
Silicon Dioxide (SiO2)
mineral
Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite organic gemstone
mineral
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineral
Moss Agate / Chalcedony
Silicon Dioxide (SiO2)
mineral
Pearl
Calcium Carbonate (CaCO3) in the form of orthorhombic Aragonite and Conchiolin
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Yellow Ochre / Limonite
Limonite (FeO(OH)·nH2O)
Mineral
Fossiliferous Rock (likely Dinosaur Fossil in Matrix)
Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)
sedimentary
Petrified wood
Silicified wood, commonly quartz/chalcedony (SiO₂) replacing wood tissue
fossil
Tumbled black-and-white stone, likely dalmatian jasper
Quartz-rich porphyritic rhyolite (commercially called dalmatian jasper), with black aegirine/arfvedsonite-like inclusions
igneous
Amber
Amber (Fossilized Tree Resin)
Mineral
Amber
Fossilized Tree Resin
gemstone
Weathered agate or chalcedony nodule
Microcrystalline quartz (SiO₂), likely agate/chalcedony with iron-oxide staining
mineral
Turquoise in Matrix
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper aluminum phosphate)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Epidosite
Epidosite (Metasomatic calcium-aluminum silicate rock)
metamorphic
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
Fossilized Coral (Petrified Coral)
Lithostrotionella (example genus) / Scleractinia
fossil