My family found rocks, with marble-shaped holes, on the beach in Washington this summer. What causes the perfectly round holes?

Can you post pictures?

It might have been water wear. It is also possible that you found water-worn bricks. Pictures would help me be able to better tell.

I am such a novice on all this! I know how to add photos as an attachment, or post them on Ebay, but how do I add them here? The items we found are definitely NOT bricks. They are truly rocks. I just can't figure how water wear could have caused such perfectly circular holes. One rock has the hole worn all the way through. Another rock has many small holes. They look as though they were made intentionally, but I don't believe they were. I hope I will be able to post the photo I just took!

I am such a novice on all this! I know how to add photos as an attachment, or post them on Ebay, but how do I add them here? The items we found are definitely NOT bricks. They are truly rocks. I just can't figure how water wear could have caused such perfectly circular holes. One rock has the hole worn all the way through. Another rock has many small holes. They look as though they were made intentionally, but I don't believe they were. I hope I will be able to post the photo I just took!

Can you host them on photobucket, or another image hosting site, and post links?

<a href="http://s656.photobucket.com/albums/uu282/ivycrafter/?action=view&current=000_0001.jpg" target="_blank"><img src="http://i656.photobucket.com/albums/uu282/ivycrafter/000_0001.jpg" border="0" alt="strange rocks"></a>

<a href="http://s656.photobucket.com/albums/uu282/ivycrafter/?action=view&current=000_0001.jpg" target="_blank"><img src="http://i656.photobucket.com/albums/uu282/ivycrafter/000_0001.jpg" border="0" alt="strange rocks"></a>

Hope this works! Thanks for the

Quote:

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Originally Posted by ksolomon

<a href="http://s656.photobucket.com/albums/uu282/ivycrafter/?action=view&current=000_0001.jpg" target="_blank"><img src="http://i656.photobucket.com/albums/uu282/ivycrafter/000_0001.jpg" border="0" alt="strange rocks"></a>

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here, fixed it for you ^_^

http://i656.photobucket.com/albums/u...r/000_0001.jpg

it really does look like water wear. My guess is that there was a softer material there that the water dissolved and then it just enlarged the holes left behind.

no matter how it was caused, those are amazing rocks. I love rocks like that and keep the ones I find ^_^

The holes are probably caused by date mussels. They secrete an acid where they cement themselves to the rock, which disintegrates the rock forming a perfect burrow surrounding their shell. At Jalama Beach in Santa Barbara County, CA, I have found rocks like this with the mussels still inside. Paste this into your browser: beach holes