The invention relates to a mechanical seal assembly comprising a mechanical seal with a rotating slide ring and a stationary slide ring, wherein one of the two slide rings has a first slide surface, wherein the other of the two slide rings has a second slide surface with a circumferentially closed sealing blade which protrudes from a bottom region of the second slide surface in the direction of the first slide surface by a height (H), wherein the sealing blade has a width (B) in a range of between 10 and 500 μm, wherein at least one pre-tensioning element braces the slide rings against each other, wherein the second slide surface and the sealing blade on the second slide surface have a diamond coating.