Is this Petrified Wood or Marine Plant/Animal?

[Jen Marie]

Hi,

I found this piece of stone in a southwestern Arizona desert.  I thought it was petrified wood and tumbled/polished it and made into a necklace 2" x 1".

 

  But I am having second thoughts that maybe it is really a fossil marine plant or animal?  The area I was in was under water at one time.

 

Thanks,

Jen Marie

 

[val horn]

I think it may be agate without a fossil.  It is very pretty.

[Rockwood]

It is pretty, but agate hunter can be a fussy bunch. 

[minnbuckeye]

Agatized Stromatolite???

[Rockwood]

Red algae might be on the list too.

[Jen Marie]

Thanks for everyone's suggestions!  I'm leaning on the idea that it is a piece of Agatized Stromatolite from what I read about that fossil.  It is the right color, and I found it in an ancient sea bed in Southwest Arizona.   I collect stone agates, and I've never seen one with these markings or color.  But I'm not an expert.