I don't know how true it is, but I remember reading in the comments section of a youtube video of Sapphire that she'd been killed in an auto accident while riding her scooter. I haven't done much looking around to verify this claim...since I'm still trying to figure out how and when Dana Douglas passed away, and haven't turned up anything on her at all...but if anything maybe this could be something to look into to verify her possible whereabouts.
I too was captivated by Sapphire pretty much right off the bat years ago. It's kind of a shame that she seemed to stop smiling all together in her last few videos...makes you wonder if she started to really hate doing porn...but she's provided many a yummy pic set and video just the same.
Where ever you are Sapphire, just know that we miss you.