Milky Quartz
Silicon Dioxide (SiO2)
mineral
Category
Sedimentary And Metamorphic
Browse sedimentary and metamorphic specimens identified by the Rock Identifier community.
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Calcite
Calcite (CaCO₃, Calcium Carbonate)
Mineral
Red Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
sedimentary
White Agate / Chalcedony
Silicon Dioxide (SiO2)
gemstone
Tiger's Eye
Silicon dioxide (SiO2) - Pseudomorph after crocidolite
mineral
Unidentifiable Rock Fragment
Uncertain
Quartz
Silicon Dioxide (SiO2)
mineral
Mixed rock and mineral collection
Multiple specimens; visible pieces may include quartz, calcite, agate/chalcedony, jasper, and dyed or coated materials
mineral
Mixed mineral and rock collection
Predominantly quartz varieties, including amethyst, plus likely calcite, feldspar, mica, and miscellaneous polished stones
mineral
Chalcedony (Agate) Pebble
Silicon Dioxide (SiO2)
mineral
Green Aventurine
Silicon dioxide (SiO2) with fuchsite inclusions
mineral
Quartz Vein in Pelite (Metamorphic Rock)
Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)
metamorphic
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
White Quartz Star-cut crystal
Silicon Dioxide (SiO2)
mineral
Tumbled hematite (likely hematite-rich ironstone)
Hematite, Fe₂O₃; possibly mixed with magnetite or goethite
mineral
Native Silver Nugget
Silver (Ag)
mineral
Pyrite
Iron Pyrite (FeS2)
mineral
Limonite pseudomorph after Pyrite
Goethite/Limonite FeO(OH)·nH2O
mineral
Milky Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
mineral
Yellow Agate
Agate (Varietal form of Chalcedony/Quartz, SiO2)
mineral
Pyrite on Quartz matrix
Iron Disulfide (FeS2) on Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Green Opal
Hydrated Silica (SiO2·nH2O)
mineraloid
Jasper
Silicon dioxide (SiO2)
sedimentary
Jasper (Red and Yellow)
Silicon Dioxide (SiO2) with iron oxide impurities
sedimentary
Brecciated Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Turquoise (Dyed Howlite/Magnesite imitation)
CuAl6(PO4)4(OH)8·4H2O (Target mineral) / MgCO3 (Magnesite substrate)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Quartz Vein in Hematitic Siltstone
Hydrothermal Quartz (SiO2) in Ferriferous Matrix
metamorphic
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Green Aventurine
Aventurine Quartz (SiO2 with inclusions of Fuchsite)
mineral
Red Jasper
Jasper (Silicon Dioxide Si₂O₃)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Beach Pebbles and Quartz Aggregates
Quartz pebbles and biogenic fragments (SiO2, CaCO3)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
sedimentary
Jasper (Red Jasper)
Silicon Dioxide (SiO₂)
sedimentary
Quartz Vein in Matrix (Breccia / Host Rock with Quartz)
Silicon Dioxide (SiO2) in Host Rock Matrix
metamorphic
Quartz Vein in Host Rock (Likely Slate or Shale)
Hydrothermal Quartz (SiO2) in Pelitic host rock
metamorphic
Unidentified weathered rock fragments
Likely mixed silicate rocks; specific identification requires testing
mineral