Mabel's wedding tiara is not the second setting of the Sapphire Tiara but the top row of stones are from the Sapphire tiara. They replace the original brown or chocolate diamonds (i have never seen an image of the original version though and there has been no appearance of the chocolate diamonds in any other form to my knowledge).
Both Maxima and Beatrix have in recent years often worn brown and beige outfits that would have suited the use of brown diamond brooches or earrings.
--Previous Message-- : Mabel will most likely be in her wedding : tiara so the sapphire tiara is out for : Maxima and Beatrix. : : I thought it was disproved a couple of years : ago the the diamond prong tiara is a second : setting of the sapphire tiara. I think Erik : S. had an article about it. Something about : the tiara was made using diamonds that had : been taken from the sapphire tiara led to : the confusion. I think now both tiaras are : completely separate and can be worn in their : full forms separately. :