Satin Spar (often marketed as Selenite)
Fibrous Gypsum (CaSO4·2H2O)
Category
Browse mineral (variety of chalcedony) specimens identified by the Rock Identifier community.
Satin Spar (often marketed as Selenite)
Fibrous Gypsum (CaSO4·2H2O)
Apatite
Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))
Milky Quartz
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Yellow tumbled/rough chalcedony, possibly citrine or dyed agate
Chalcedony (microcrystalline SiO₂), with yellow coloration likely from iron oxides; exact identification is uncertain from the photograph
Quartz
Silicon dioxide (SiO2)
Quartz (Cut and Polished Sphere)
Silicon Dioxide (SiO2)
Quartz or possibly Jasper/Chert. Looks like a tumbled or water-worn stone.
SiO2 (Silicon Dioxide)
Green Aventurine
Aventurine (a variety of Quartz, SiO2)
Zebra Jasper (with Chlorite/Epidote)
Silicon Dioxide (SiO2) with inclusions
Petrified Wood
Silicified Wood (SiO2)
Agate
Silicon Dioxide (Quartz), SiO2
Dyed Agate
SiO2 (Silicon Dioxide)
Ocean Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
Dendritic Agate (Tumbled)
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Black Onyx
Silicon Dioxide (SiO2) with layered chalcedony
Dendritic Quartz
Silicon Dioxide (SiO2) with Manganese Oxide inclusions
Carnelian Agate
Silicon Dioxide (SiO2)
Agate
Agate (Cryptocrystalline Quartz, SiO2)
Quartz (Orange/Pink variety)
Silicon Dioxide (SiO2)
Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
Dalmatian Jasper (or Dalmatian Stone)
Dalmatian Stone (A peralkaline felsite composed of feldspar, quartz, and sodic amphibole)
Moss Agate Geode Sphere
Silicon Dioxide (SiO2) - Chalcedony with Chlorite or Manganese inclusions
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Chert (Chalcedony / Gray Flint)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Chalcedony (Carnelian / Agate)
Silicon Dioxide (SiO2)
Tumbled purple agate (likely grape agate or amethystine chalcedony)
Microcrystalline quartz, SiO₂; purple coloration commonly from iron, manganese, or inclusions
Yellow Chalcedony (or Yellow Jasper / Agate)
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Fire Agate
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
Yellow Chalcedony (Agate/Jasper mix)
Silicon Dioxide (SiO2)
Green Onyx (Banded Calcite)
Calcite (Calcium Carbonate, CaCO3)
Chalcedony (Agate/Seashell replacement)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Crazy Lace Agate
Cryptocrystalline Quartz (Silicon Dioxide, SiO2)
Chalcedony (Agate/Quartz)
Silicon Dioxide (SiO2)
Moss Agate
Silicon dioxide (SiO2) with inclusions of hornblende or chlorite
Chert (specifically varieties like Chalcedony or Flint)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)