This close-up shows the edge of Champagne Pool in the Waiotapu thermal region, south of Rotorua. The pool has a water temperature of about 75°C. The orange material is sulfur (containing small amounts of arsenic and antimony), which has precipitated underwater onto thermophilic micro-organisms. The small, conical objects are called spicules. These are formed by numerous layers of micro-organisms that have become encased in fine-grained silica deposited from the cooling water. The blue-green patches are cyanobacteria and algae.