Banded Calcite (often marketed as 'Mexican Onyx')
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Category
Organic Gem Material (Botanical)
Browse organic gem material (botanical) specimens identified by the Rock Identifier community.
Chert (Honey Chert / Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Chert (variously known as Flint or River Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Obsidian Arrowhead
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Soapstone (Steatite)
Steatite (primarily Talc: Mg3Si4O10(OH)2)
metamorphic
Banded Calcite (Cave Onyx)
Calcium Carbonate (CaCO3)
sedimentary
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
mineral
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Tektite (Indochinite)
Tektite (SiO2 + Al2O3, Glassy Melts)
igneous
Biotite (Mica)
K(Mg,Fe)3AlSi3O10(OH,F)2
mineral
Bauxite
Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))
sedimentary
Quartz (Milky/Yellowish variety)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2) in Host Rock
sedimentary
Tiger's Eye
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
Mineral (Metamorphic pseudomorph)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Mineraloid
Basalt (Crushed Stone Aggregate)
Mafic Volcanic Basalt (Major Minerals: Plagioclase Feldspar, Pyroxene, Olivine)
igneous
Diamond
Diamond (pure Carbon, C)
mineral
Crushed Limestone (Gravel)
Calcium Carbonate (CaCO3)
sedimentary
Amygdaloidal Basalt with Zeolite/Quartz Infill
Amygdaloidal Basalt (Host: (Mg,Fe)2SiO4 / CaAl2Si2O8; Infill: SiO2 or Na2Al2Si3O10·2H2O)
igneous
Diamond (in jewelry setting)
Adamantine Carbon (C)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Diamond
Diamond (pure Carbon, C)
mineral
Chert Pebble (Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (specifically Jasper or Flint type)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
sedimentary
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper-bearing)
Chert (Silicon Dioxide, SiO2)
sedimentary
Fancy Jasper
Silicon dioxide (SiO2)
sedimentary
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
sedimentary
Red Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Pink Chert (Brecciated Jasmine/Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint Nodular)
Chert (Silicon dioxide, SiO2)
sedimentary
Quartz (Engineered Stone Countertop)
Silicon Dioxide (SiO2) with polymer resins
Sedimentary-like (Industrial Composite)
Limonite
Limonite (Hydrated iron(III) oxide-hydroxide) FeO(OH)·nH2O
mineral
Slag (Industrial Glassy Byproduct)
Anthropogenic silicate byproduct (Slag)
Mineral-like byproduct (often mistaken for igneous rock or meteorite)
Limonite (vibrant yellowish-brown iron oxide)
Limonite (FeO(OH)·nH2O)
mineral
Anthracite Coal
Anthracite
sedimentary