“A petrified tooth… a piece of history in the palm of your hand”

The image is divided into two shots of the same object, held between someone’s fingers and in front of a keyboard: 1. Left shot:
The tooth is visible from the front. It’s triangular in shape, curved, and dark gray to black with a sheen. Its edges have beige residue of hardened dirt and clay. 2. Right shot:
The tooth is visible from the side. It’s very thin and razor-sharp. Its thickness and cutting edge are visible. What is this, really? This is most likely a fossilized shark tooth 🦈.