Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
Category
Browse organic mineral specimens identified by the Rock Identifier community.
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
Amber (Copal)
Fossilized Tree Resin (C10H16O)
Amber
Succinite (Resinite), C10-H16-O
White Coral
Corallium rubrum (biocarbonate calcium) / CaCO3
Limestone (specifically Bituminous or Carbonaceous Limestone)
Calcium Carbonate (CaCO3) with Organic Impurities
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Jasper
Jasper (Silicon Dioxide, SiO2)
Green Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Red Moss Agate (Jasper)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Amber
Amber (Succinite), fossilized tree resin
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Shungite
Non-crystalline carbon (allotrope of carbon)
Amber / Copal
Fossilized Tree Resin (Succinate)
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)
Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
Jasper Agate
Silicon dioxide (SiO2)
Precious Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
Pyrite in Shale
Iron Disulfide (FeS2)
Mother of Pearl and Onyx
Aragonite (Mother of Pearl) and Chalcedony (Onyx)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Amber
Succinite
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
Moss Agate / Chalcedony
Silicon Dioxide (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with mineral inclusions
Moss Agate
Chalcedony (Silicon Dioxide) with inclusions - SiO2
Amber
Succinite (fossilized resin)
Dendritic Agate
Chalcedony (SiO2) with manganese/iron oxide inclusions
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide
Amber
Succinite (Formula: C10H16O)
Amber
Fossilized Tree Resin (Succinate)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Pearl
Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3
Amber
Succinite (fossilized resin)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
Amber
Succinite (fossilized resin, C10H16O)
Amber
Succinite (specifically for Baltic amber); Chemical formula approximately C10H16O
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Chert
Silicon dioxide (SiO2)