Granite
Granite (Felsic intrusive igneous rock)
Category
Browse organic (geological relative) specimens identified by the Rock Identifier community.
Granite
Granite (Felsic intrusive igneous rock)
Fluorite Bracelet (light green beads) and possibly Lavender Jadeite (purple bead)
Fluorite: CaF₂ (Calcium Fluoride); Jadeite: NaAlSi₂O₆ (Sodium Aluminum Silicate)
Fluorite (likely)
Calcium Fluoride (CaF2)
Firewood (Wood Log)
Lignum (Plant tissue composed of cellulose and lignin)
Ambergris
Ambrein-rich Calculus
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Pearls
Aragonite (calcium carbonate) and Conchiolin
Brachiopod Fossil (Spiriferid)
Phylum Brachiopoda, Order Spiriferida (CaCO3 - Calcium Carbonate)
Petrified Wood
Silicified wood, primarily composed of Quartz (SiO2)
Calcite
Calcite (Mineral, Calcium Carbonate - CaCO3)
Marble
Marble (primarily Calcite, CaCO3 or Dolomite, CaMg(CO3)2)
Serpentinite
Serpentinite (a rock composed predominantly of serpentine group minerals)
Peridot
Olivine (Mg,Fe)2SiO4
Amber
Amber (Fossilized Tree Resin)
Chert (varietal known as Jasper or Flint)
Silicon Dioxide (SiO2)
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Sulfur on Aragonite
Sulfur (S) and Aragonite (CaCO3)
Petrified Wood
Silicified wood (Quartz/Chalcedony)
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Amber
Fossilized Tree Resin (Amorphous Hydrocarbon)
Marble
Metamorphosed Limestone/Dolomite
Amber
(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.
Wood Jasper
Siliceous sedimentary rock (variety of Chert/Chalcedony)
Serpentine
Serpentinite (a rock composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite; general formula (Mg, Fe)3Si2O5(OH)4)
Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Serpentine
Serpentine group minerals (e.g., Antigorite, Chrysotile, Lizardite). Chemical formula: (Mg, Fe)₃Si₂O₅(OH)₄
Jasper and Aquamarine (likely)
Jasper (Cryptocrystalline Quartz (SiO2)), Aquamarine (Beryl (Be3Al2Si6O18))
Conglomerate
Conglomerate
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Baroque Pearl (and potentially a small Sapphire/Blue Topaz)
Pearl: Calcium Carbonate (aragonite or calcite) with conchiolin. Sapphire: Aluminum Oxide (Al2O3). Blue Topaz: Al2SiO4(F,OH)2.
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Chalcedony Geode
Chalcedony (SiO2) within a geode structure
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Ambergris (Sea Wax)
Physeter macrocephalus fecalith
Shale (possibly)
Shale (fine-grained clastic sedimentary rock)
Red Coral
Corallium rubrum (for precious red coral), although other species like Corallium japonicum and Paracorallium are also used.
Flower Agate (Plume Agate)
Chalcedony (Silicon Dioxide) with Spherulitic Inclusions - SiO2
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
Obsidian
Amorphous volcanic glass (70-75% SiO2)
Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
Orange Calcite
Calcite (CaCO3)
Flower Agate (Cherry Blossom Agate)
Chalcedony (Silicon Dioxide) with Opaque Inclusions - SiO2