Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Category
Organic Mineraloid And Mineral
Browse organic mineraloid and mineral specimens identified by the Rock Identifier community.
Kyanite
Kyanite (Al2SiO5)
Mineral
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Petrified Wood
Silicified wood (Quartz/Chalcedony)
Sedimentary
Granite (Specimen: Logan Rock)
Phaneritic plutonic igneous rock (mainly Quartz, Feldspar, and Mica)
igneous
River Rock
Sedimentary Rock (various compositions)
sedimentary
Chalcedony Geode
Chalcedony (SiO2) within a geode structure
Mineral Geode/Sedimentary or Volcanic related
Pyrite
Pyrite (Iron Disulfide), FeS2
Mineral
Wood Jasper
Siliceous sedimentary rock (variety of Chert/Chalcedony)
Sedimentary
Polychrome Jasper (Desert Jasper)
Silicon Dioxide (SiO2) with iron and mineral inclusions
sedimentary
Jasper (var. Ocean or Polychrome Jasper)
Silicon Dioxide (SiO2) with iron and mineral inclusions
sedimentary
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
Quartz
Silicon Dioxide (SiO₂)
Mineral
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Sedimentary or Metamorphic (low grade)
Bismuth
Bismuth (Bi)
mineral
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Organic Gemstone/Biomineral
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 ).
Mineral, Organic Gemstone
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Sedimentary or Metamorphic (low-grade)
Amber (Simulated/Faturan Style)
Resin mix (Likely Phenolic/Celluloid if synthetic, Succinite if natural)
Organic Gemstone (not a mineral)
Biological Bone (Patella/Knee)
Patella (part of the Human Skeletal System)
Organic Structure (Not a Rock)
Greisen
Greisen
Metamorphic
Chert (varietal known as Jasper or Flint)
Silicon Dioxide (SiO2)
Sedimentary Rock
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Metamorphic Rock
Fossil Shark Tooth (Cretaceous white shark type)
Squalicorax (commonly known as Crow Shark)
Organic specimen (fossil)
Banded Chert
Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)
Sedimentary
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and mineral impurities
sedimentary
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and mineral inclusions
sedimentary
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and mineral impurities
sedimentary
Aragonite (variety 'Flos Ferri')
Aragonite (CaCO3)
Mineral
Calcite
Calcite (CaCO₃, Calcium Carbonate)
Mineral
Granite Gneiss
Gneiss (derived from granitic protolith)
metamorphic
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Sedimentary
Pebble (river rock/beach pebble)
Pebble (clast size class)
Sedimentary Rock
Greywacke (likely)
Greywacke (a type of sandstone)
Sedimentary
Petrified Wood
Silicified wood, primarily composed of Quartz (SiO2)
Mineral, often found in sedimentary deposits
River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Sedimentary Rock (possibly composed of various minerals)
Chevron Amethyst
Quartz (SiO2) with patterned Amethyst and White Quartz/Milky Quartz
mineral
Banded Gneiss (Variety of Gneiss)
Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)
Metamorphic Rock
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Sedimentary Rock
Greisen (Quartz-Muscovite-Turretine Rock)
Greisen
Metamorphic Rock
Fossilized Shark Teeth
Carcharhiniformes or Lamniformes species (common mineral: Fluorapatite/Ca5(PO4)3F)
sedimentary (fossilized organic matter)
Blue Lace Agate
Chalcedony (a form of Quartz) - SiO2
Mineral