Amethyst
Amethyst (Silicon Dioxide, SiO2)
Category
Browse sedimentary (secondary mineral formation) specimens identified by the Rock Identifier community.
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (often colloquially referred to as Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Red Jasper
Silicon Dioxide with Iron Oxide (SiO2)
Red Jasper (possibly Brecciated)
Jasper (Silicon Dioxide, SiO2)
Fossil Coral
Coral Limestone (a type of biogenic sedimentary rock)
Goethite
Goethite (α-FeO(OH))
Amazonite
Amazonite (KAlSi3O8) - a variety of Microcline Feldspar
Lapis Lazuli (Tumbled Specimen)
Lapis Lazuli (Aggregate rock containing Lazurite: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)
Granite Cobble
Phaneritic Felsic Igneous Rock
Granitic Gneiss
Gneiss (Polymetamorphic Granitic Gneiss)
Amethyst
Amethyst (SiO2 with Iron impurities)
Limestone
Calcium Carbonate (CaCO3)
Fossil Coral
Scleractinia (Anthos), primarily Calcium Carbonate (CaCO3)
Chert (variations include Flint/Jasper)
Cryptocrystalline Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Red Jasper
Silicon Dioxide (SiO₂)
Red Jasper
SiO2 (Silicon Dioxide with Iron inclusions)
Lapis Lazuli
Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Blue Dyed Agate Geode
Chalcedony (cryptocrystalline Quartz), SiO2
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Garden Quartz (Lodolite)
Quartz with inclusions (SiO2 + various inclusions such as Chlorite, Hematite, or Feldspar)
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)
Caliche (also known as hardpan, calcrete, kankar)
Primarily composed of calcium carbonate (CaCO₃), often mixed with other minerals like quartz, clay minerals, and iron oxides.
Azurite-Malachite (often called Azerite Malachite or Azurmalachite)
Azurite (Cu3(CO3)2(OH)2) and Malachite (Cu2CO3(OH)2)
Lapis Lazuli (polished cabochon)
Lazurite-rich metamorphic rock (approx. Na6Ca2Al6Si6O24(SO4,S,Cl)2)
Amazonite (likely mixed with other feldspars/minerals)
Amazonite is a variety of Microcline, which is a tectosilicate mineral, formula KAISi3O8. The mixed beads could include other feldspars or quartz.
Chert (Flint)
SiO2 (predominantly microcrystalline or cryptocrystalline quartz)
Rose Quartz
Quartz (SiO₂), specifically a variety of Quartz
Moonstone
Orthoclase Feldspar (KAlSi3O8)
Agate with Quartz Druzy
Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline varieties
Rose Quartz
Silicon dioxide with traces of titanium, iron, or manganese (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Greenstone
Metabasalt / Chlorite-Epidote Schist
Grey Limestone Pebble
Limestone (Calcium Carbonate - CaCO3)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese