Platinum and diamond rings- how old are they? *lots of photos*

I found these while going through some of my late great-aunts things. I would love to know about when they were made so perhaps I can determine who they would have belonged to. She supposedly lost her wedding ring years ago which was the only diamond she had, so I am doubtful that they are hers. But anything is possible!

They are both marked with the tiny triangle in this photo > http://farm5.static.flickr.com/4025/4491685352_b2a4e64b9a_o.jpg

and they are both also marked with "10% Irid Plat"
(here's a photo > http://farm3.static.flickr.com/2715/4491685188_397547f041_b.jpg )

and here is a side view
> http://farm5.static.flickr.com/4025/4491685352_b2a4e64b9a_o.jpg

And that's all I know!

Thanks in advance for any information you might give me!