Weapon skin laying around...

craybest

So I was doing some summerset quest in riven spire, and around the big castle with the tall towers, on the lower right of the map, I found a big purple glow on a small hill. I approached it, interacted with it and I got a new mace skin. First time this happens to me. I thought it might be some kind of event or something but I don't see anything related to this.
Anyone care to explain what it is and if there are more like that?

static_recharge

You had a Glenmoril Wyrd map in your inventory from the witches festival. Each map gave a different weapon.

craybest

Ah I had no idea thanks!