If genuine that would be a clipped planchet (not a planchet chip). edit Your clipped planchet appears to be genuine but I cannot tell for sure from your photo.
You're right. My mistake. I'll try to get more pictures for you to look at it better. The iPhone isn't the best quality camera I could have used, but I used it.
There appears the be the Blakesley effect on the reverse around 9 o clock, so if thats what it is, it is genuine.