Manganese Dendrite on Siltstone
Manganese Oxide (pyrolusite or psilomelane) Dendrites
mineral/sedimentary
Category
Organic Crystal (Mineraloid)
Browse organic crystal (mineraloid) specimens identified by the Rock Identifier community.
Amber and Citrine Quartz
Succinite (Amber) and Silicon Dioxide (SiO2 / Citrine)
mineral
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
sedimentary
Black Limestone with Calcite Veining
Bituminous Limestone (CaCO3 with Organic Carbon inclusions)
sedimentary
Amber
Succinite (fossilized resin, C10H16O)
mineral
Likely fossil shell fragment
Indeterminate mollusk fossil; possibly a gastropod or bivalve in limestone
fossil
Petrified Wood
Silicified wood (Quartz replacement, SiO2)
fossil
Amber
Succinicum (C10H16O)
mineral
Amber
Succinates (Fossilized Resin)
mineral
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
sedimentary
Pyritic Shale
Carbonaceous Shale with Iron Pyrite (FeS2)
sedimentary
Chert (Green Fossilized Algae or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Raw Amber / Resin Mineral
Succinite (Fossilized Tree Resin)
gemstone
Limestone (specifically Bituminous or Carbonaceous Limestone)
Calcium Carbonate (CaCO3) with Organic Impurities
sedimentary
Amber
Amber (C10H16O)
mineral
Chert (Jasper/Chalcedony mix)
Microcrystalline Quartz (SiO2)
sedimentary
Fossiliferous Shale
Carbonaceous Shale (with potential plant/aquatic fossils)
sedimentary
Cullet (Slag Glass)
Amorphous Silica (SiO2) with various metal oxide colorants
mineraloid / anthropogenic
Natural Pearl
Calcium carbonate (primarily Aragonite and Conchiolin), CaCO3
mineral
Grass (Organic Matter/Soil)
Poaceae (family of monocotyledonous flowering plants)
Organic Materia (Not a rock or mineral)
Opalite (Synthetic Moonstone/Opal)
Synthetic Silica Glass
mineraloid (synthetic)
Amethyst, Aquamarine, and Pearl Ring
SiO2 (Amethyst), Be3Al2Si6O18 (Aquamarine), CaCO3 (Pearl)
gemstone
Man-made Glass (Tumbled/Shaped)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Mineraloid (synthetic)
Amber
Succinite (fossilized resin)
mineral
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
sedimentary
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary (or mineraloid)
Ambergris
Physeter macrocephalus excreta (Ambergris)
mineraloid / organic geological find
Sea Glass
Amorphous Silica (SiO2) with various additives
Mineraloid (Anthropogenic)
Black Chert
Carbonaceous Chert (Silicon dioxide, SiO2)
sedimentary
Opalite
Synthetic Glass, SiO2 base with metallic inclusions
mineraloid (synthetic)
Amber
Succiniferous fossil resin (C10H16O)
gemstone
Moldavite
Silica glass with small amounts of aluminum, iron, and other elements
Mineraloid / Tektite
Opalite
Synthetic Fluorescent Glass (SiO2 + impurities)
mineraloid (synthetic)
Opalite
Synthetic Opalised Glass
mineraloid (synthetic)
Slag (Industrial Glass Slag)
Amorphous Silica / Ferro-silicate Slag
mineraloid / anthropogenic
Fossilized Shell in Limestone
Bivalve fossil (CaCO3) in Carbonate Sedimentary Rock
sedimentary
Amber
Succinite (C10H16O)
mineral
Amber
Succinite (Approximate formula: C10H16O)
mineral
Petrified Wood
Silicified Wood (SiO2)
fossil
Amber
Succinite (approximate formula C10H16O)
mineral
Amber
Succinite (fossilized organic resin)
mineral
Amber
Succinite
mineral