Pearl or marble?
In this picture, the turquoise rectangle on the sphere is the reflecttion of my phone case (if any confusion)
Recently, I was at a small beach in Shediac, New-Brunswick, when I saw a patch of around 50 hermit crabs gathered in the same place. I looked closely and realized they were fighting for a blueish pearl of around 15mm of diameter, which I think is pretty big for a saltwater pearl and around the size of a marble. The pearl is a perfect sphere, and the reflections on it are sharp and clear. I have done some research, but i'm not sure if the sphere is a marble or a saltwater pearl. Could anyone tell me what it is? Thank you.