dissimilarity

noun

1. (countable, uncountable)A lack of similarity or a lack of likeness in appearance to something else.

   “The experiment was abandoned when one fine day spontaneous combustion of the pulverised coal in the container occurred, and a black cloud of the very finely divided fuel rose into the air by the force of the explosion, and was slowly wafted by the prevailing breeze over the town, upon which it descended with the resemblance of black snow, but with the dissimilarity that it did not melt.”