This beautiful necklace looks incredible during the day with the help of the UV reactive uranium glass but at night under black light it glows a beautifully bright green color! On me this necklace is more of a choker at 14 1/2 inches long. It has a hook on one end as a clasp. One section of the necklace does not glow. When these rhinestone necklaces were created they were unaware that they were using uranium glass so it is very common to get a necklace with only a few pieces that glow, but for this necklace most of it glows except for a few places that don''t!