Large Septarian Nodule polished sphere, gorgeous. Measures just over 6" in diameter. Weighs approx 10 pounds. Available with or without stand. The unique markings are fascinating. Stand Measures 4" tall. Septarian Nodules formed between 50 to 70 million years ago. Septarians are composed of Calcite (The Yellow Centers), Aragonite (The Brown Lines), and the outer grey rock is Limestone.