Genuine 1981 10 cent curved clipped planchet error. Note thinning of rim next to clipped portion of coin. Also note the flatness of the rim opposite the clipped region of the coin which is known as “Blakesley Effect”. Basically the rim of the blank in this area was not formed properly when put through the rimming machine due to the missing part of the coin opposite. The Blakesley Effect is more obvious on the reverse of the coin. There is also some fishtailing of the obverse lettering, again an indication that this is a genuine clip.
How to Determine if a Clipped Planchet is Real – Australian Coin Collecting Blog, accessed 31 October 2013