Many, many people in that part of the world are familiar with lapidary techniques. And cheap jadeite is often waxed to fill in polishing pits, which might account for the luster on the beads in question.
Just because it's jade doesn't mean it's expensive. And just because it was purchased in Burma doesn't mean it wasn't cut in Shenzen...

If you paid a lot for the beads and really want to know what the stone is, there are gemological labs in southeast asia that can do an ID for you for a modest fee.