Photos: Return of the zeppelin Summary: From hundreds of feet in the air, a zeppelin can scan a landscape for hints of diamond deposits. By Bill Detwiler | July 19, 2006 -- 11:46 GMT (04:46 PDT) Follow @billdetwiler Previous | Next Image 4 of 6 Envelope The envelope of the NT airship, made of many layers of laminated fabric, holds helium gas. Topic: Telcos Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.