Agate

    The spiral shells in this specimen of "turritella agate" are actually from another species of mollusk. However, the name is still commonly applied to this variety. "'Turritella Agate' (chertified fossiliferous lacustrine limestone) (Laney Member, Green River Formation, Middle Eocene; North Barrel Springs Draw, south of Wamsutter, Wyoming, USA) 4" by James St. John is licensed under CC By 2.0

    Article: Agate Value, Price, and Jewelry Information

    Credit: James St. John

    GemstoneAgate, Chalcedony, Quartz
    Natural or man madeNatural
    OriginUnited States
    Origin detailsNorth Barrel Springs Draw, south of Wamsutter, Wyoming
    Gem StateRough
    ColorWhite
    TransparencyOpaque