looking for title of old early 80's sci fi story about a character called Death

I am trying to recall a book I enjoyed many years ago but cant remember the title or author:
early to mid 80"s (I read it before I graduated from high school which was 1984)
Science Fiction paperback along the lines of Piers Anthony (on a Pale horse) but none of his seem to match.

*it was about a charcter who was the Angel of death (Reaper) I beleieve he was just plainly called Death, discribed as being carved from obsidion with white flowing hair
*a woman made a deal with him (not sure what it was on) but when her time was up she was to join him as his companion.
*Once in the underworld she turned into the wife from hell. She torments Death to such an extent he leaves the underworld and roams the surface world.
*There are a few times she is able to escape but in doing so her body turns blue and one finger decayed to bone, Death had offered to cast a spell to make it look pretty again but she refused because her appearance tormented him further.
*Throughout the story who grow to pitty Death, because the woman was just down right mean mean mean. She developed a nick name Mrs. Death/Death's bride???

This is about all I can remember at this time.

Does anyone know what book this is????

Word of advice never never ever get rid of your books, if you really enjoyed readying it... keep it.

please post or email me direct pso777@earthlink.net

I think this is Tanith Lee's Death's Master, part of her Flat Earth series - creepy but good!

I concur. I only reread this a couple of years ago, so the book is still kinda fresh in my mind.

You two are AWESOME!!!!
I looked it up and ure enough its the one.
THANK YOU VERY MUCH!!!!