When Maria tells us that she has a pearl and ruby necklace, we are led to believe that this is a new gift, not something that has been used to woo her into marrying Henry. They must have been married before the gift was given. In fact it is likely that this is a wedding gift from Henry to Maria. So Henry must have attracted Maria in a different way. But as all we are given is this information, we must assume that Henry has been giving his ex-wives' possessions as gifts for a long time. How did he get all these items back? Maybe he was rich once and they had to sign some sort of pre-nuptial agreement that said that in the event of a divorce, said gifts had to be returned to Henry as to show that the women never married Henry for his (then) wealth. Well done Henry!
The most puzzling point here is that they are all near a jeweller's. This implies that Henry has had to come up with some elaborate facade in order to trick Maria into thinking he was buying the necklace and not just re-giving it. This must have involved some careful planning and the co-operation with the proprieter of the jeweller's shop. What must he have thought when Henry wanted to use his shop as a front to give his wife a necklace that he already owned? Perhaps Henry didn't tell the jeweller and merely took it in the week before to have it cleaned and valued, thus tricking both his new wife and the jeweller. He must have had faith that his plan would work as the jeweller could have said at anytime that he had cleaned it and it was never purchased at that jeweller's and therefore ruining his entire plan. No wonder Henry looks quietly pleased. His plan worked without a hitch. That said, he probably did the same trick for his second wife.