Rainbow Fluorite
Calcium Fluoride (CaF2)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Rainbow Fluorite
Calcium Fluoride (CaF2)
Gold (in Opaque Matrix/Jewelry)
Native Gold (Au)
Fossil Crab
Decapoda (likely Avitelmessus or Raninidae family)
Milky Quartz
Quartz (SiO2)
Amber
Succinite (approximate formula C10H16O)
Siderite Concretion in Shale
Iron carbonate (FeCO3) in Mudstone/Shale matrix
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Jasper containing fossilized inclusions
Silicon Dioxide (SiO2) with trace impurities and biogenic inclusions
Moss Agate / Chalcedony
Silicon Dioxide (SiO2)
Cuprite
Cuprite (Copper(I) oxide, Cu2O)
Sodalite in Matrix (often called Blue Marble or Sodalite-Syenite)
Sodalite-bearing Syenite / Na8Al6Si6O24Cl2 (Sodalite component)
Amber
Succinates (fossilized tree resin), approximately C10H16O
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
Amber
Succinite (C10H16O)
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions of Chlorite, Manganese, or Iron
Chert Nodules in Limestone
Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
Chert / Flint
Chert (SiO2)
Shungite
Non-crystalline carbon (allotrope of carbon)
Malachite
Copper Carbonate Hydroxide (Cu2CO3(OH)2)
Arfvedsonite in Quartz (also labeled as Astrophyllite or Nuummite by collectors)
[Na][Na2][Mg4Fe2+](Si8O22)(OH)2 in SiO2
Black Pearl (Tahitian Type)
Aragonite / Pinctada margaritifera (CaCO3 + Conchiolin)
Pearl (likely Freshwater or Akoya Cultured)
Aragonite / Conchiolin composite (CaCO3)
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)
Amber
Succinite (a variety of fossilized tree resin); chemical formula appx. C10H16O
Fossiliferous Limestone
Calcium Carbonate (CaCO3)
Moss Agate
Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)
Moss Agate
Silicon Dioxide (SiO2) with inclusions
Pearl
Organic Mineraloid (CaCO3 + Conchiolin)
Amber
Succinite (Approximate formula: C10H16O)
Citrine
Quartz (SiO₂) variety
Glauconitic Sandstone
Glauconitic sandstone ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Jasper
Chalcedony (cryptocrystalline quartz), SiO2
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
Arfvedsonite in Quartz (also known as Eudialyte/Garnet Syenite variety)
Arfvedsonite [Na3(Fe2+)4Fe3+Si8O22(OH)2] within a silicate matrix
Azurite
Azurite (Copper Carbonate Hydroxide), Cu3(CO3)2(OH)2
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
Travertine
Travertine (a terrestrial form of Limestone, CaCO3)
Fossil Shark Tooth
Carcharodon sp. (likely Otodus or similar Lamniformes order)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide