Darkness is lack of light. It is an uncreated, unmanifested nothing.
Seeing how darkness is the absence of light, It is a bit strange that “darkness” is a noun, but then again, “nothing” is also, somehow, a noun.
“Light does have weight, meaning that it is a source of gravitational fields. A box of light weighs more than an empty box. The reason is that ALL forms of energy have weight. However, under ordinary earthly conditions, the weight of light is insignificant compared to other weights.
SOURCE; GOOGLE Result http://van.physics.illinois.edu/qa/listing.php?id=1395 from search for, “Does Light Have weight?”.
Darkness, it turns out, is lighter than light.