This is the second skink I saw in Tasmania. I think it may be Carinascincus metallicus (Metallic skink), in a Soft Tree Fern forest near St. Columba Falls. Apparently Niveoscincus metallicus is the former name, now Carinascincus metallicus. This is the most common garden skink in Tasmania:
http://www.parks.tas.gov.au/indeX.aspX?base=5414