What kind of pearls are these?

I'd say fake looking at the colour and uniformity. Davey is right though, with the tooth thing. Won't tell you if they're cultured though.

 

Yes I do feel a gritty texture like sand

 

In that case, real, but I suspect cultured rather than natural. Especially with that modern lobster claw clasp. Natural would have something far better.

 

I just bought a cluster of six strings of pearls like this at a bead store. I promised my nieces pearl necklaces. I haven't done any jewelry in a long time, but still have all the findings. The uniform size indicates cultured to me.

 

I use to rub the pearl on one of my teeth but started to get strange shocking looks at the thrift store. So I swapped up and I now just gently rub two of the pearls on the string together and I find that I feel the same light gritty texture if they are real or a smooth feel if they are faux.