it's a Rokkor-X made by Minolta for an XG-1 MD mount camera. My other two lenses don't have it, but this has what appears to be a rubberized/cork-like washer around the rear glass that has white specs and bumbs all on it. Is it supposed to look like this or is this fungus on part of the lens, the stuff that usually grows on the glass that everyone fears? I've never seen this before.

Do you have a digital camera? It's hard to make a judgement without seeing it. It does sound like it could be fungus, though. Does it come off with a damp cloth? I'd try that.

I don't have a digital camera. Imagine the material that makes spray on bed liners and imagine it to have a very dark brown color with bits of white that doesn't come off with a whipe.

I'm no expert on the MD lenses, having come along in the Maxxum era. But neither have I seen anything like you're describing come from the factory, on Minolta or any other lens.

The way you describe it, sounds like a sloppy home repair job. Like a previous owner may have dismantled it for an internal cleaning (yes, it can be done) then had some difficulty reassembling it - having to improvise a rear gasket, for example. I've never seen the factory use Cork.

It would be best, like Photo-John says, if we could have a good close look at this for better diagnosis. Actual pictures are a lot more telling, than even the most detailed description.

Don't have a digicam? Find a friend who does. Switch into macro mode and fire away. Or sit it down on a flatbed scanner and scan it. Something to get us a clear color image of this.