Wai-O-Tapu, "sacred waters" in Maori is an active geothermal area close to Rotorua in the north island of New Zealand. This picture is a detail of the Champagne Pool one of the main attraction. The top part is water with bubbles of CO2 rising from the depth of the spring, the vibrant orange and the grey-white parts are two different precipitates. The first one is composed of sulphur and silica while the second one which is underwater is composed of sulphur with high heavy metal.