You can see good luster on a few of the forward pearls in the second picture. You can also see a slight pink hue.
Pearlies,
White freshwater pearls are always treated. Selecting lustrous rounds from "raw material," as they call it in China, is extremely difficult, and the only way to do it is to select them individually from a first-stage factory. Pearls aren't considered ready for sale until they go through the third stage. Raw material, for the most part, is not very attractive. We have a box of them here that we keep for a Buddhist Temple. Every year they fill a statue with round to near round raw material, so we get it sent to us as a favor.
All whites go through the same bleaching and heat treatments, and from the pink overtone, the strand has also had some pinking done to it.