Interesting Limb Cast. Id like to hear opinions.

The center/heartwood does not always decay at the same rate as the outer/sapwood. One does occasionally find pieces where the center and hard knots did not decay away completely, and instead mineralized/petrified—the petrified wood core retains preserved grain and different color due to the heartwood having more mineral content, and the outer is just an agate cast of the limb exterior. Sometimes the petrified cores are very fragmented and/or show extensive evidence of rots (very interesting), and sometimes there is a transition zone between cast and petrified heartwood. Limb and tree casts form in different orientations (standing, fallen and lying horizontally, root casts, etc.), so there are multiple possible explanations. If the piece was standing vertically, it is unlikely that anything fell down into, or grew through, the center with agate already forming around it.

Anything is possible, however, and if it were lying horizontal, then a cast might potentially collapse and another branch fall into a partially filled void. The latter would be rare, especially if it were to land in the center of a cast and oriented the same direction, and you'd have some indication/interruption in any banding or other pattern in the agate that indicates a break in the filling (i.e., the agate banding wouldn't likely be continuous or even all around the intruding stick). In the case of an intrusion, the agate would form around the intruding limb differently than in the case of a heartwood core being preserved in situ in the center of a branch or log. Would be nice to see more segments of the limb in that case.

To my eyes, the OP looks like petrified heartwood at the core of a cast.


Gotta agree with that