Chert (Chalk-associated Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse organic gem material (botanical) specimens identified by the Rock Identifier community.
Chert (Chalk-associated Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Man-made Carved Stone (Scream Mask/Skull motif)
Carved Soapstone or Serpentine-rich rock
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions (SiO2 + Fe2O3)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Siltstone
Siltstone (composed of clastic quartz and feldspar)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Limestone
Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 based)
Jasper and Chert Conglomerate
Ferruginous Microcrystalline Quartz (SiO2)
Asphalt (Bituminous Slate/Sandstone)
Asphaltum / Bituminous Rock
Milky Quartz
Silicon Dioxide (SiO2)
Sandstone (River Cobble)
Arenite
Peridot (Olivine)
Olivine ((Mg, Fe)2SiO4)
Quartz / Milky Quartz
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Green variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Marble
Recrystallized Calcite (CaCO3)
Coquina or Fossiliferous Limestone
Biogenic Limestone (Calcite/Aragonite CaCO3)
Vesicular Basalt
Mafic Volcanic Rock (Basalt)
Quartzite
Quartzite (SiO2)
Pumice
Pumice (a highly vesicular volcanic rock)
Quartz (specifically Clear and Rose Quartz)
Silicon Dioxide (SiO2)
Sandstone (Flagstone)
Arenite (composed primarily of SiO2)
Granite (Weathered)
Course-grained Intrusive Igneous Rock
Crushed Stone (Likely Granite or Diabase)
Intrusive Igneous Rock (Granitoid/Gabbroid)
Chert (Pink/Red variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Yellow/Common Opal or Jasper mixture)
Silicon Dioxide (SiO2)
Jasper (Petrified Wood variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Grey and White Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Tan/Yellow Chert)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
Banded Chert
Cryptocrystalline Quartz (SiO2)
Kyanite
Kyanite (Al2SiO5)
Sandstone
Arenite (primarily SiO2)
Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
Peridotite (with Olivine and Pyroxene)
Ultramafic Magmatic Rock (Primary minerals: (Mg, Fe)2SiO4 and (Ca, Mg, Fe)2Si2O6)
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
Chalcedony (Agate/Chert)
Microcrystalline Quartz (SiO2)
Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')
Calcite (Calcium Carbonate, CaCO3)