Geological Dopers: Attention. OK, I'll Bite--What are they??

Factual Questions
1

Check the link–

http://www.borderlandnews.com/stories/borderland/20050130-17498.shtml
These are some of the dammest things in the way of rocks I’ve ever seem.

Fossils?
Geodes?
Conglomerations of mineral crystals?

2

Looks like chert. Maybe a casting of the interior of a large brachiopod?

3

It’s impossible to tell what it is with only a tiny picture to go on. Could be a coral.

4

Petrified muffins?

5

Dwarven battle scones.

6

I have to agree with this. If I saw it lying around, that is exactly what I would think it was. The thumb size depression on the bottom would be from the muscle attachment scar.

7

Reminds me of the formations I saw in Peche Merle caves in France. There were limestone “tops” there that looked a lot like the illustration - see this photo which shows one “top” and several “pearls”. These are formed by moving water in a limestone cave. The “pearls” are tumbled, while the “tops” get spun around - this causes the sort of shape seen in Bosda’s original link.

Maybe this guy bought the rocks from a cave explorer?

8

They say it is made of Silica, a mineral, and you can create mineral structures quick by solving a mineral in water (try boiling water and dissolve a lot of salt in it, then after a bit of cooling down pour it into a glass, and leave the glass standing for a few weeks and wait for the water to dissolve. Very nice effect. You’ll have a glass for drinking Margerithas to last you a lifetime. :D)

So what I would be looking for is a place where high concentrations of Silica occur in the vicinity of water. So I google “Silica water” and come up with this:

  1. Silica phases are widely found in waste storage environments; and 2) Silicate minerals comprise >90% of the earth’s crust and dominate virtually every repository rock-water system.
    (http://www.geol.vt.edu/geochem/pmd/SummarySilicaWaterInteraction.html)

So, that seems to make this theory fairly likely. Now we need to find a container that allows water to run into it, and dissolve in such a way that Silicate minerals can reform into the shape we see in the rock. For instance, somewhere where there is tropical rain. The rain may pick up minerals from the rocks the water runs over, and then ends up in some kind of natural pocket where during the rest of the day it evaporates again (as could plausibly happen in a rainforest, I assume).

To help determine the location, I would suggest taking a much closer look at the rocks than so far seems to have been done, to determine the level of pollution with among others other minerals. That could help pin-point the origin.

  • disclaimer *
    The author of this post is not a geologist. He does not claim to have authority on this subject whatsoever, other than that he has personally tried the glass/salt thing as a kid. He has also tried it with sugar, but it wasn’t as purdy. Peers that happen to dwell in his vicinity after a while usually discover that many of the plausible sounding explanations he gives of mysterious things in our environment can indeed be plausible sounding, but not necessarily true.