B. Jayne Keele of Clarkston was doing the job she has done for 18 years checking clothing before it hit the big Blue Ribbon Laundry washers.

She attached identification tickets to a pair of shirts and ran her hands over the pockets. In one was a small piece of tissue paper.

Keele could have pitched it, as she does wads of Kleenex and bits of trash a dozen times a day. Instead, she unfolded it.

In her hand lay a glittering tear-shaped stone the color of golden-brown cognac and about as large as the nail on her little finger.

Retail manager Ron L. Asker was standing nearby. ''I said, 'Ron, look at this. Is it real?''' Keele repeated Friday. ''He said, 'Well, I'd better find out.'''

It was 8 a.m. Wednesday morning when Asker called the home of the shirt's owner. ''I just told her we found a jewel and I'd like to get it off my hands as soon as possible,'' Asker said.

The woman who answered the telephone started to cry.

It was a real 1.65 karat diamond valued at about $6,000.

Deanna Haines came right down to claim it, Asker said.

Michael Haines, owner of the Diamond Shop in downtown Lewiston, said he was packing the stone around because he was designing a custom setting for it. ''It's not unusual. That's the business I'm in,'' he said.

But usually he empties all his pockets at the end of the work day. This time, the tissue package must have wedged in the bottom of the pocket because he missed it and the shirt was packed off to the cleaners.

It is an unusual stone, a ''natural fancy,'' he said. ''I would have missed it. I would have wondered what happened to that.''

It probably would have gone down the drain if Keele's fingers had missed it Wednesday morning. ''It would have been a big loss,'' she said.

''It was gorgeous. It just sparkled. It was so pretty,'' Asker added.

It never crossed either of their minds to do anything but try to find the owner, Keele and Asker said.

''It's pretty much standard policy to return things we find in pockets,'' Asker said.

But what they usually find are pens, rubber bands, receipts, used tissues, a few credit cards, and the occasional oddity, like last week's two condoms.

The most valuable find either could remember before the credit cards aside was an occasional $5 bill.

Of course, the most important finds from her perspective in the laundry are pens and lipstick, especially lipstick, because they mess up a whole load of laundry, Keele said.

The Haineses gave Keele a gift certificate in appreciation for recovering the stone. She picked out a ring set with two small diamonds. ''Nothing like what I found,'' but hers to keep, she said happily.

''It was certainly not the worth of the diamond, but it was just something we could do to show our appreciation,'' Michael Haines said. ''It's nice to know there are some honest people out there.''