Looks like a water worn piece of mollusk shell. Certain species add layers of shell as they grow like clams.I've found many shells like this but never in perfect rectangular shape like yours. Awesome find , most likely a shell.
Looks like a water worn piece of mollusk shell. Certain species add layers of shell as they grow like clams.I've found many shells like this but never in perfect rectangular shape like yours. Awesome find , most likely a shell.