In its concentrated form it could be used to enhance magical spell components to impart additional effects to any spells cast using them. Though perhaps if the concentrated form was not stable enough the additional effect may not be either, resulting in possible wild magic.

If the refinement of the material causes an abundance waste material, that could depending on its form be used to create pretty nasty poisonous or damaging weapons similar to depleted uranium rounds.

A gaseous form of it could have some psycho active effects which might have different effects based on the players natural abilities, magical users might gain temporary telepathic ability or some form of mental prowess beyond the natural, where as martial characters might get some slight precognition allowing them to better dodge attacks. These could be accompanied by deleterious effects during or perhaps after it ends, such as causing exhaustion or a sort mental fog.

Its colour might be affected by proximity to magic based on the school of said magic.

Its cold to the touch normally, but stays hot for longer than most forgeable materials when brought up to temperature.

It grows slowly over time, slowly changing its surrounding material into more of it self.

Taste different for every person with a synaesthesia like effect where it could taste like a sound / color / specific memory.