These objects are undoubtedly very ancient. Just image Julius Ceasar was sailing up the Nile with Cleopatra and these stone objects of yours were sitting around just the same as they are now.
When the ancient Sumerians of Nippur were reading the Epic of Gilgamesh to their children 4,000 years ago, your stones were still the same.
When Otzi the Ice Man was minding his own buisness walking atop the Alps before being savagely murdered over 5,300 years ago, your items were still here.
When the planet Theia slammed into Earth 4.5 billion years ago the atoms that made up your rocks were probably somewhere mixed up in it all.
So let the naysayers unbelievers have their fun but you'll have the last laugh knowing these stone things are older than anything they've ever found.
Come to think of it on a molecular level everything is pretty much equal in age, subatomicly dirt and gold are both made of the same particles... why do we even do this treasure hunting nonsense when everything is essentially the same? Subatomicly a pound of dirt and a pound of diamonds are both just each a pound of electrons, protons, and neutrons. We humans are so silly.