Nanometre‐scale spheroids on sands, Vulcano, Sicily: possible nannobacterial alteration

Spheroids in the size range of 30–200 nm coat sand grains on sediments around the island of Vulcano. They occur as single individuals, as ball‐shaped clumps resembling biological colonies with radiating chains of bodies, and eventually merge into sheets in which the individual nannobacteria are no longer evident. Rarely, they appear to bore into the glass grains. Older rocks are composed mainly of closely packed nanospheroids. These spheroids are believed to be nannobacterial cells based on their resemblance to nannobacteria found in other surficial environments, and their occurrence in colony‐like groups. If so, nannobacteria play a very important role in the destruction of volcanic materials on Vulcano.