Answer:
It's been around for millions of years, but it's no more than a month old. What is it?
What leaps one time out of four?
I occur twice in eternity. And I'm always within sight.
This is a pearshaped fruit with a rough leathery skin, smooth oily edible flesh, and a large pit in the center. It is most used in guacamole dip
It is in every mountain, it's not in any hill, it's not in all the world, and yet it's in the mill.
I go in hard come out soft. Blow me hard and I’ll make a pop.