When we walk along a river side it is not so infrequent to see rocks, pebbles, sands, cobbles, boulders or stones.

Every stones has a story to tell, generally a very long story.

Let’s have a look at a big cobble, for example.

Before meeting me, it travelled along the river bed at the mercy of the water stream. Its shape was originally squared, but the action of water and sand particles made it to be rounded like a sort of heavy ball.

And before to be a cobble, it was a rock making part of a mountain.

But if we look carefully at its texture, we see its history before becoming a part of a mountain.

Yes, there is an older part of the history as the cobbles is made by thousands of particles, each with its color and composition: quartz, mica, different small rocks fragments and so on.

Before becoming a cobble it was a rock, but before becoming a solid and strong rock, glued to the flak of a mountain, it was a lose sand trapped in a turbid flow moving quickly along an ancient seabead.

And the history would be not finished here, we could continue to go backwards, telling about an ancient mountain chain eroded by the rains, ice a water flows giving rise to that sand and so on.