Each weapon that drops has a (small) chance of being a 'seal' weapon. There are four types of seals, although one is not drop-able. Seal of Star is your basic seal, which basically adds +5 to your weapon, then moon with +10, and sun with +15. The glows on weapons mean they are seal weapons. The SHINES on weapons mean they are +3 (white shine), +5 (purple), +7 (yellow) and +9 (blue).
As for the balls around peoples waists, you're probably referring to an ice of fire buff, which adds to your magical (fire) or physical (ice) defence. Lasts 4-10 minutes depending on the level of buff..
Crumpets for Pres