not a diamond ring, right?

The Landver spike onyx ring. This could definitely be used as a weapon, I can see it now:

A girl walks alone stumbling on her sky-high heels down a dark, dark alley way, trying to make her way to the nearest street to hail a taxi. After a late night out, she appears more or less in tact. Just a few extra rips in her tights and some splatters on her black satin. She wears her Landver spike onyx ring. As she continues down the alley, she is dimly aware of being followed; the substances consumed still hazing over all sensory input. The sights and sounds of the street are yards away, she quickens her pace just in case. He does the same. She is completely alert now. She hears him mutter a grotesque pick-up line. He's only a few feet away. Then she feels a grab on her shoulder. Her reflexes tell her to scream, but instead she balls the Landver ring-ed hand into a fist and throws her best punch. As she darts away, she hears cries of pain echoing in the alley.

Hope that story was mildly entertaining. Ta-ta for now...