Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Category
Mineraloid (Human Made Geological Specimen)
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Banded Agate (likely Carnelian Agate or Sardonyx)
Agate is a common name for a microcrystalline variety of Quartz (SiO₂), specifically a form of Chalcedony.
Sedimentary Rock (technically a variety of Chalcedony)
Nephrite Jade
Nephrite (a variety of the mineral actinolite within the amphibole group); Chemical Formula: Ca2(Mg,Fe)5Si8O22(OH)2
Mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Quartz
Quartz (Silicon Dioxide - SiO2)
Mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Massive Cryptocrystalline Quartz (Chert/Chalcedony Pebble)
Silicon Dioxide (SiO2)
sedimentary
Pink Granite
Phaneritic Felsic Igneous Rock
igneous
Mica Schist (with Golden/Biotite inclusions)
K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)
metamorphic
Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt containing Zeolite and Calcite inclusions
igneous
Diamond in Kimberlite
Kimberlite Matrix with Carbon (Diamond)
igneous
Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
sedimentary or igneous
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
sedimentary
Quartz
SiO₂ (Silicon Dioxide)
Mineral
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Sedimentary
Rough Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Black Tourmaline (Schorl)
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
mineral
Petrified Wood
Silicified wood (Quartz/Chalcedony)
Sedimentary
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
mineral
Aquamarine
Beryl (Be3Al2Si6O18), specifically the blue-green variety
Mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese
mineral
Septarian Nodule (or Mudstone with Septarian Cracking)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Claystone)
sedimentary
Gold Ore in Matrix
Native Gold (Au) in Quartz/Limonite host rock
mineral
Amygdaloidal Rhyolite
Amygdaloidal felsic extrusive rock
igneous
Oolite or Oolitic Limestone
Oolitic Limestone (Principal mineral: Calcite, CaCO3)
sedimentary
Emerald In Matrix (Quartz/Calcite)
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Sedimentary Rock
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Graphite Schist
C (Carbonaceous Schist)
metamorphic
Sandstone
Arenite
sedimentary
Granite
Granite (a common term for a felsic intrusive igneous rock)
igneous
Petrified Wood
Silicified Wood (SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2 permineralization)
sedimentary
Druzy Quartz Geode (Oco or Moroccan variety)
Silicon Dioxide (SiO2)
mineral
Sandstone with Quartz Vein
Arenite with Quartz (SiO2) Infilling
sedimentary
Stromatolite
Biogenic Sedimentary Rock (Lithified microbial mat)
sedimentary
Brachiopod Fossil (Spiriferid)
Phylum Brachiopoda, Order Spiriferida (CaCO3 - Calcium Carbonate)
sedimentary (fossilized organic remains)
Ironstone Concretion (Moqui Marble variety)
Ferruginous Sandstone Concretion
sedimentary