Mysterious Beach "Rock" Find

September 10, 2014 10:22 PM

I expect this will turn out to be something akin to a lump of interesting concrete, but please take a gander at this object from a beach near Port Townsend, Washington, and tell me what you think it might be.

The "rock" in question is about 3" across at its widest point, and has the heft of quartz or similar stone. It does not "crumble" when rubbed and is a lot denser than something like natural bone or similar material. The center section surrounded by the teeth-like "nodules" is rough, but the sides and much of the dished side are relatively smooth.

My guess is it may be mineral secretions left behind by a sea creature, or some sort of man-made object which has been radically modified by seawater...but I don't know. I'm very reluctant to suggest it's a fossil of some sort, though the area is somewhat known for dropping mammoth remains out of the glacial-till cliffs around here.

Some photos, please excuse their quality:

One | Two | Three | Four

Even if this proves to be something mundane you'll make my aged parents happy with an ID of their find!

posted by maxwelton to Science & Nature (9 answers total)

A wild guess, but it looks like weathered marble. Might have been a victorian era decoration of some sort.
posted by boilermonster at 10:28 PM on September 10, 2014

Best answer: It resembles the base of a naturally shed antler, as if it had been broken off when it was in velvet, healed, and then the stump was shed naturally at the end of its season.

Check it with a microscope.
posted by the Real Dan at 11:20 PM on September 10, 2014 [2 favorites]

Response by poster: Having just gone off to explore the exciting world of mule-deer antlers via image search, that is a damn fine theory. I would have sworn this was denser than bone, but I also have no experience of antlers, mine never grew in (though my eyebrows are definitely on their way there).

Still a neat thing to find. As a kid (and adult, I'll admit it) I longed to find a set of shed antlers, but never have--despite living most of my life in rural-ish environs overrun with the creatures.
posted by maxwelton at 1:59 AM on September 11, 2014 [2 favorites]

2nding the antler thingee. I'd call it a Unicorn stub.
posted by Gungho at 5:40 AM on September 11, 2014 [1 favorite]

You say this seems denser than bone... perhaps it's been altered by long exposure to sea water? (And I posit that 'long exposure' from it's somewhat rubbed appearance, sort of how sea glass or old shells get worn/battered.)
posted by easily confused at 5:41 AM on September 11, 2014

You can buy shed antlers at any nice pet store (dogs love chewing on 'em) if you want to verify it's the same substance. Definitely looks like antler to me.
posted by town of cats at 7:35 AM on September 11, 2014

Maybe fossilized? Like example #4 here.
posted by neroli at 7:51 AM on September 11, 2014

Response by poster: Fossilized is definitely a possibility, as it definitely seemed like a mineral and not bone, and my parent's Boston Terrier expressed no interest in it. The idea that long exposure to sea water could have done something to the bone to make it "denser" is also an idea, and I have no idea if antlers in general are more solidly constructed than, say, a femur.

Thanks again for the ideas and answers!
posted by maxwelton at 9:48 AM on September 11, 2014

Since I don't know about antlers, my thought was that the overall shape is similar to an oyster shell.
posted by SemiSalt at 11:53 AM on September 11, 2014