This pictures are showing clearly it isn't a rock, either a mineral. It is origen organic. Feels smoothly in the hand and the shiny in the sunlight it was the reason for me to take a deeper look and pick it up.
A rock never is built by nature with tiny little balls. I don't have experience with pearls. I was searching for any information I could find in the www . They are so many different kinds to find.
Curious thing is that looks like little tiny pearls .
The weight and the size is not the same...