Perfect Sphere, manufactured railing/decoration found in Curiosity latest images

Several anomalies found in Curiosity SOL 746 and SOL 753.

In the first image two anomalies, a perfect sphere and an unnatural object what probably is petrified.

Link original image SOL 746

In the next image two anomalies, the left object looks like a manufactured railing or decoration on a fence or maybe on top of a building, the second object to the right looks like a very small body/head.

Link original image SOL 753