Sometimes a piece of sea glass with a bright, unique glowing color washes up. If the piece is a vibrant, limey green, it may glow even more brightly under a black light.
It is likely that the sea glass piece has originated from a Uranium Oxide (diurnate) glass piece that may have come from pre-1930 pieces of table ware and Depression Glass.
It also was popular during the Victorian era (but not likely if it is a Pacific, West Coast piece). This bright, oftentimes yellow glass was popularly named Vaseline Glass because it frequently resembled the color of the petroleum jelly of the same name.
Many tableware pieces were created with such chemicals with the purpose of giving the glass carafe or vessel a yellowish or bright green color.