Cobalt Crust. Terana caeruleaThis beautiful blue crust fungus is listed in some of the older books (my Michael Jordan's Enc) as Pulcherricium caeruleum.
I haven't seen it for a few years and when I looked it up it is described as "infrequent". The books say most commonly found on Ash or Hazel as was this specimen, however I have found it in the past growing on Bramble. It can be used to produce an antibiotic named cortalcerone that inhibits the growth of Streptococcus pyogenes, a spherical bacterium that is responsible for an abundance of infections, so one of the more useful fungi.