Alternatively, just fire a highly upgraded Mining Laser in all directions in hope of hitting the ore that you can't see. Item Magnet augments are useful when doing this.
Tips
A common mistake is to seek Effigium in subbiomes (not in the main biome) of the Lightless planet. Effigium will exist in Lightless or Lightless Cave biomes, but subbiomes have their own ores (and most likely won't have any Effigium).
