Sandstone Geode (Unbroken)
Siliciclastic sedimentary rock (primarily Quartz)
sedimentary
Category
Man Made Object (Simulant)
Browse man made object (simulant) specimens identified by the Rock Identifier community.
Quartz Druzy Geode
Silicon Dioxide (SiO2) - Crystalline Variety
mineral
Basalt River Pebble
Basalt
igneous
Orca Agate (Chalcedony)
Silicon Dioxide (SiO2) with inclusions
mineral
Pink Granite
Granite (Alkali-feldspar granite)
igneous
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Mineral
N/A (This is a digital image of a bar graph)
Digital Data Visualization (Bar Chart)
This is not a rock or mineral
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
mineral
Milk Quartz (Common White Quartz)
Quartz (Silicon Dioxide, SiO2)
mineral
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Quartzite
Quartzite (SiO2)
Metamorphic
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
igneous
Ambergris
Ambrein (C30H52O)
mineraloid / organic geological substance
Granite
Phaneritic Felsic Igneous Rock
igneous
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Mineral
Serpentine
Serpentinite (rock), Serpentine group minerals (e.g., Antigorite, Lizardite, Chrysotile)
Metamorphic rock
Chert (Flint)
Chert (microcrystalline quartz)
sedimentary
Chert (or Flint)
Silicon dioxide (SiO2)
sedimentary
Stromatolite
Laminated biogenic sedimentary structure (formed by Cyanobacteria)
sedimentary
Schorl (Black Tourmaline) in Quartz or Feldspar Matrix
NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl) in Granitic Pegmatite
igneous
Druzy Quartz on Matrix (likely Limestone or Sandstone)
Silicon Dioxide (SiO2) with various trace impurities
Mineral on Sedimentary Rock
Basalt
Mafic volcanic rock (Silicon dioxide 45-52%)
igneous
Mahogany Obsidian Arrowhead
Volcanic Glass with Hematite/Magnetite inclusions (Amorphous Silicon Dioxide)
igneous
Obsidian (Apache Tear)
Obsidian / Amorphous Volcanic Glass (main component: SiO2)
igneous
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
Quartz (likely Rose Quartz or Milky Quartz based on color)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Granite (weathered)
Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Limonitic Sandstone with Inclusion
Limonitic Quartz Sandstone (primarily SiO2 with FeO(OH)·nH2O)
sedimentary
Queen Conch Shell (Biogenic Calcium Carbonate)
Aliger gigas (synonym Strombus gigas); Composition: Aragonite (CaCO3)
mineral
Quartz (beads)
SiO2 (Silicon Dioxide)
Mineral
Smoky Quartz
SiO2 (Silicon Dioxide)
Mineral
Fuchsite
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
mineral
Marble
Marble (primarily Calcite, CaCO3 or Dolomite, CaMg(CO3)2)
Metamorphic Rock
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Epidote with Quartz and Feldspar
Ca2(Al2,Fe3+)(SiO4)3(OH) (Epidote complex)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Red Garnet
Pyrope-Almandine series (Mg3Al2(SiO4)3 to Fe3Al2(SiO4)3)
mineral
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
igneous
Ambergris
Ambrein (C30H52O Derivative)
Organic (Zoogenic)
Quartz
Silicon Dioxide (SiO2)
Mineral
Quartz
Quartz (Silicon Dioxide, SiO2)
Mineral