Wyoming Mystery Rock

[Miatria]

A couple of my friends went on a rockhounding/fossil hunting trip throughout Wyoming and Utah in June of this year. They made so many stops and picked up so many rocks that something was bound to get lost in the shuffle. What got lost was the ID of this rock.

The outside of the rock looks almost like a chunk of old, pitted cement, but when I slabbed it, I found a beautiful interior.

The slab in the photo is approx. 10cm x 11cm with a swirled pattern of solid pinkish stone and more translucent quartz/chalcedony. The slab is 7mm thick and has several holes all the way through it.

It doesn't look like photos I've seen of palm wood and it doesn't look like the petrified wood I am familiar with from Arizona and Wyoming.

Any ideas?

[jpc]

Some sort of petrified wood is a good guess. Where did it come from?

[Rockwood]

Without knowing the age I don't think you should rule out fern as a possibility.

[ynot]

It looks like a volcanic with a lot of gas bubbles that partly filled with agate. Not of biologic origin. Just My opinion.

Either way it is a nice rock!

Tony

[caldigger]

Looks like tufa to me. Calcious rock created by heavily mineralized water upwelling into lake environments... Google Mono Lake.

[abyssunder]

Travertine?

[ynot]

Travertine?

No. Travertine does not have the voids and has a layered appearance.

Tony

[Leiavara]

It looks a lot like a calcedony rock that I have found in the Sierra. Opalized with a lot of crystaline voids.