Mirror chromium nitride layer

A mirror with a visible transmission of no more than 1.5% comprising: a substrate supporting a coating, wherein the coating includes at least one reflective layer comprising chromium nitride, wherein the nitride comprising capareflectante chromium is graduated with nitrogen so that a first portion of lamisma contains more nitrogen than a second portion thereof, in the chelates graduation may be continuous or stepwise from the portion of the far delsustrato reflective layer to the portion of the nearest the glass substrate reflective layer so that the portion of the far sustratotenga capareflectante a nitrogen content of less than the portion nearest the glass substrate reflective layer.