2" Stromatolite Sphere Black Brown Natural Crystal Ball Polished Algae Fossil Mineral Stone - Peru + Plastic Stand (#2) You will receive exactly this Stromatolite Sphere - 51mm / 2 Inches Diameter; 185g / 6.5 oz (see photo, the photos are taken under bright light, stand included)! Stromatolites are one of the oldest fossils known, some dating to over 3.5 billion years old. Stromatolites are actually structures formed by huge colonies of blue green algae (or cyanobacteria). Some scientists consider these bacteria to be the earliest life form on Earth. The cyanobacteria which dominate stromatolites process many of the building blocks of life, including oxygen, carbon, and nitrogen. Stromatolites provides some of the most ancient records of life on earth. The banding that commonly appears in stromatolite is a record of the growth patterns of colonies of microorganisms. Stromatolites or stromatoliths ( from the Greek stroma, meaning bed, and lithos, rock) are layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms, especially cyanobacteria. Type: Fossil; Color: Black, Brown; (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.)