Siderite Concretion in Shale
Iron carbonate (FeCO3) in Mudstone/Shale matrix
sedimentary
Category
Organic Gemstone (Sedimentary Associations)
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Polished pink-and-gray stone, likely rhodonite-bearing rock
Rhodonite (MnSiO₃) in a manganese-rich metamorphic matrix; exact identification requires testing
metamorphic
Amethyst and Citrine (Quartz variants)
Silicon Dioxide (SiO2)
mineral
Moss Agate
SiO2 (Cryptocrystalline Quartz)
gemstone
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Fossilized Tooth Fragment
Vertebrate Fossil (Mammalia indet.)
fossil
Amber
Succinite (fossilized tree resin)
fossil
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
mineral
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Moss Agate
Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)
mineral
Fluorite on Matrix
Calcium Fluoride (CaF2)
mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
Mineral
Quartz on Chlorite Schist
Chlorite Schist (Mg,Fe)3(Si,Al)4O10(OH)2 with Quartz (SiO2)
metamorphic
Fossiliferous Limestone / Petrifaction
Sedimentary rock with fossil inclusions / Calcium Carbonate (CaCO3)
fossil
Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
sedimentary
Dyed Pink Quartzite (Jadeite Simulant)
Silicon Dioxide (SiO2) with organic dye
metamorphic
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions
mineral
Amethyst Quartz
SiO2 (Silicon Dioxide)
Mineral
Chert Nodules in Limestone
Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
sedimentary
White seed-bead gemstone strand, likely freshwater pearl or shell pearl
Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image
gemstone
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Jasper containing fossilized inclusions
Silicon Dioxide (SiO2) with trace impurities and biogenic inclusions
sedimentary
Graphite
Carbon (C)
mineral
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Jasper
Microcrystalline quartz (SiO2)
sedimentary
Fossilized Shark Tooth (Partial) or Coprolite
Elasmobranchii (fossil) or Coprolite (trace fossil)
fossil
Chert / Flint Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Graphite
Graphite (Carbon, C)
mineral
Chert (Yellow Jasper)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper variation)
Silicon Dioxide (SiO2)
sedimentary
Amber
Succinite (approximate formula C10H16O)
mineral
Fossiliferous Limestone
Biogenic Sedimentary Rock
sedimentary
Amber
Succinate (Fossilized Tree Resin)
mineraloid
Amber
Succinite (Organic Mineraloid)
mineral
Rose Quartz
Silicon dioxide (SiO2)
mineral
Amber
Succinate (Fossilized Resin)
mineral
Pearl (likely Freshwater or Akoya Cultured)
Aragonite / Conchiolin composite (CaCO3)
Mineralloid (Organic gemstone)
Quartz-veined Limestone
Sedimentary limestone with quartz/calcite veinlets
sedimentary
Natural Pearl (appearing in a jewelry setting)
Calcium Carbonate (mostly Aragonite), CaCO3 with Conchiolin
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
mineral