[Rockhounds] ID help

[Jim Murowchick]

They look more like drip tubes than worm tubes to me.  Worm tubes usually
have much thinner walls--thick walls would be a lot of work, as Pete pointed
out.  Are the holes truly round, or could there be faces from overgrowth on
a subsequently-dissolved acicular mineral?

I've seen similar tube structures of pyrite formed (according to Mavrogenes)
by H2S bubbles exiting the wall of a cavity, then rising upward. With a
little oxidation, pyrite can form, producing a small chimney.

Jim Murowchick


On 7/15/08 10:56 AM, "Lawrence Rush" <larryrush at worldnet.att.net> wrote:

> Help.......all you Paleontologists...
> 
> Is this an Aragonite concretion or an example of worm tubes? I'm leaning
> toward the concretion origin, but would like a professional opinion.
> 
> (Note the centered holes in each of the "tubes")
> 
> thanks....Larry
> 
> 
> http://www.connroxminerals.com/ammonite.html