Dropped by the especially elusive field boss Nova Elemental, Marcasite Ore controls what is probably the most broken elemental in the game, with the ability to burst foes into light, dealing heavy damage if not alright destroying them outright. It is uncertain whether it will be nerfed in a new patch, but it's more likely than not to be pinned down much like the darkness elemental had been.
Much like every Elemental ore that is not Emerald, Marcasite Ore is only meant for weaponry, and it cannot be fused into armor to strengthen it. Armor can be decorated by it, which tends to be a very pleasing cosmetic appearance, but no different properties would be applied other than this cosmetic difference.
Much like the Emerald ore, Marcasite Ore-based weaponry has storage of energy for releasing the elemental, the more used at one time the longer it takes to recharge the capacity.
Properties of this light elemental Marcasite Ore will be made more clear as time goes by and are obtained by the players of the server.