This is one of three face climbs to the left of Diagonal. It has steep face climbing past pockets, jugs, and slopers to a technical move on dirty rock to top out on the ledge of Green Route. The climb continues past the ledge and is rumored to be 5.10 from there to the top via a roof.
To the left of Diagonal on Fisherman's Wall, there are three 5.9 face climbs. Topaz is the climb in the center with Babe to the left and Strawberry Fields to the right.
Usually this is done as a top-rope, although I have seen it climbed with marginal gear.