Sea Shell (Fighting Conch Fragment)
Calcium Carbonate (CaCO3) - Strombus alatus fragment
Category
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Sea Shell (Fighting Conch Fragment)
Calcium Carbonate (CaCO3) - Strombus alatus fragment
N/A (Non-Geological Specimen)
Granite
Granite (plutonic igneous rock)
Diamond
Carbon (C)
Chert (Nodular)
Chert (SiO2 - Microcrystalline Quartz)
Limonite/Ironstone
Limonite (FeO(OH)·nH2O)
Crinoid Fossil Stem Segment
Class Crinoidea (Echinodermata)
Apatite
Fluorapatite, Chlorapatite, and Hydroxylapatite (Ca5(PO4)3(F,Cl,OH))
Opal
Hydrated Silica (SiO2·nH2O)
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Black Obsidian
Volcanic Glass (SiO2 + impurities like Fe3O4)
Diamond
Diamond (pure Carbon, C)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Jasper
Silicon Dioxide (Microcrystalline Quartz), SiO2
Jasper
Microcrystalline Quartz (SiO2)
Quartz Vein in Host Rock
Silicon dioxide (SiO2) veining in silicate matrix
Waterworn Pebble / Quartzite
Metamorphic/Sedimentary rock fragment
Quartz-veined Basalt or Diabase Pebble
Igneous rock with hydrothermal quartz vein
Granite River Pebble
Granite (Phaneritic Igneous Rock)
Calamites Fossil (Horsetail Stem)
Calamites (Genus), part of the class Equisetopsida
Generic Rock / Pebble
Undetermined rock specimen
Diorite
Diorite
Green Opal
Hydrated amorphous silica (SiO2·nH2O) with inclusions
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Flint
Microcrystalline quartz (SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Pearl
Organic Mineraloid (CaCO3 + Conchiolin)
Gold Ore in Quartz
Auriferous Quartz (Au + SiO2)
Chert (Nodule)
Chert (SiO2)
Amber (Copal)
Succinate (Fossilized Resin)
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
Limonite/Goethite Concretion
Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)
Tektite (Indochinite)
Tektite (High-silica impact glass)
Chalcanthite (Likely Synthetic/Lab-Grown)
Hydrated copper(II) sulfate (CuSO4·5H2O)
Blue Slag Glass
Man-made Silicon Dioxide (Amorphous)
Conch Pearl
Calcareous concretion (CaCO3)
Malachite
Malachite (Copper Carbonate Hydroxide) - Cu2CO3(OH)2
Fossilized oyster shell
Bivalvia; likely an oyster (Ostreidae), partly mineralized with calcite