Petrified??? Help identifying strange rock

[Kathleen Anne]

This strange "rock" came out of a wall made of petrified wood/crystals/minerals etc. that is in my yard, made by the previous owners probably in the 1930's. They were avid rock collectors who obviously spent a lot of time constructing this wall. Over time the cement is crumbling and releasing these rocks. This item measures about 6 inches across, about 5 1/2 inches tall, and 6 inches in depth. It weighs about 3 lbs 4 oz.
Any ideas of what it is? I have been unable to find anything that looks similar online. Thank you for your help.

 

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[DDancer]

Looks to be chalcedony thats partially agatetized~ portions of it are agate. A transition in the mineral. Its difficult to say its just agate as it could grade out to be jasper as well depending on the viewer however the interior vug is that of chalcedony. Not uncommon to find a mixed bag when looking at this mineral. My opinion.

 

[loco oro]

My best guess is jasper

 

[Ponchosportal]

My best guess is coprolite. Has the rock been varnished?