40mm Septarian Dragon Stone Sphere Natural Yellow Brown Quartz Polished Crystal Ball Calcite Aragonite Fossil Smooth Mineral Stone - Madagascar + Plastic Stand You will receive exactly this Septarian Dragon Stone Sphere - 40mm / 1 9/16 Inches Diameter; 90g / 3.2 oz (see photo, stand included)! Septarian nodules are unique in that they were formed as a result of volcanic eruptions and attracted dead sea life chemically bonding them to the sediment and forming mud balls. They are composed of Calcite, which makes up the yellow centers and Aragonite which are the brown lines. Chemical Formula: Ca (A12Si7O18 y H2O NaCa4) (Al9Si27) O72 3O-H2O; Moh's scale (hardness): 3.5-4.0; Color: Yellows, browns, whites; Septarian also called Dragon Stone. The name Septarian comes from the Latin word "septum" meaning seven, or saeptum which means a wall or enclosure. As the balls dried they shrank inside and had a tendency to create a distinctive pattern of 7 points in every direction. (The above information is provided solely for informational purpose. Kindly note that all stones are offered for decorative purposes only. Please, handle your stones with great care, do not grind or crumble them, do not dip or add them into your food or drink, do not use any parts of them in any elixirs, potions, lotions etc. Always make sure you wash your hands before and after working with your crystals.)