I recently changed the basket on my platinum setting to a V head. Now, the seems where the basket was soldered to the mounting are turning yellowish. The jeweler said that he had to use low content platinum solder b/c otherwise all the side stone would fall out. It is a channel set baguette mounting.Do you think they used white gold instead of platinum???Aside from the fact that it now looks cheap, has the durability of the setting been compromised? The stone is a 1.8 round.Thank you for your reply.