Guild Wars 2

You click it and it show a area marked and you go there and nothing, just destroy it?

You need to interact with an object at the marked area.

That specific one is at the Skill Point down the well in the shown area.

You need to interact with the skill point and there should be an option to use the Residue.

I was confused at first too xD.

Have taken the skillpoint, have to go there again then.

If it’s your first time there you have to claim the skill point first.
If it’s your first time there and you also have 25+ quartz shards then you have to claim the skill point and then make a charged quartz thingy first.
I know when I went there I had to use it 3 times before it did what it was supposed to.

I also found that if i had any quartz crystals in my inventory then i didn’t get the correct option when using the skill point