I've been trying to remove floating shelves fixed onto a masonry wall with no visible screws. After cutting into it with a saw, I've found it is held up with the following fixing:
The exposed part of it was screwed into the wood of the shelf, and it appears the part in the wall has perhaps been set with some sort of mortar.
What type of fixing is this, and how do I remove it from the wall?
Also, I still have a bunch of shelves still in the wall that I need to take down. So far I've just been going at it with my reciprocating saw, as both my hammer drill and oscillating multitool seemed to have no impact on them. However, even with the saw, I've broken a few blades so far (possibly due to the awkward angles involved).
Is there something better I should be using to remove shelves fixed in this manner?