Nickel - Lamination Error?

I have a few planchet laminations, and that looks like one to me
Pretty dramatic example as it bisects the coin.

it's a bubble or an impurity in the the metal that gets stretched into a layer ie "lamination" when rolled out to stamp coin blanks. That's the brief answer...I'm sure the coin experts have a better one.

Yes, that is. I have many Lincoln Cent lams.
and two good points to identifying a lam. error
is the irregularity of the lines or cracks if you want to call them that, and most of the time the lines flow from the fields into the devices and or vice versa. Sometimes you can find an actual lam. that looks almost straight so it takes a little closer looking to be sure.
There are a few people out there who collect them. I saved them over the years and for the heck of it put some up for sale a few times (mostly lincoln cents) Got anywhere from a buck or two for them.
Not bad for a circ. cent.