Help? (unknown Puzzle Lol)

As by the title, i found something juicy lol located at -404 -3804 ss of the tree itself so you know what im talking about and ik this is a dark ass picture however, i found a little button i dont know what it is or the purpose of it, i was hoping to find some forum help =]

 

there are a ton of slabs and stuff, right? One of them is dark oak while others are spruce

Throw an emerald on it and go towards the outside/edge/rim of the island (Dont know the direction) and a cave should open up. It's a wand relic.

EDIT: It's on the western side, thanks @Bloodarchmage

 

if gavel was north it would be on the west @Nick Crompton

 

thanks so much for your help :)