The Smithsonian Institute has taken care of a fabulous new piece of ruby and platinum jewellery as part of its National Gem Collection.

The piece is centered around a 23.1-carat Burmese ruby, which is set in platinum to show off its beauty.

Donated by Subway sandwich chain founder Peter Buck, the piece was sent in the name of his wife Carmen Lucia Buck who had a penchant for fine jewellery.

Whilst she never wore the item, Mr Buck told the Fort Worth Star Telegram that the piece "epitomized what she liked - the finer things - and her generosity in setting up foundations for medical causes".

"So it seemed like a really appropriate thing to do, to give it to the nation so people could come and see it," he added.

Mr Buck offered an undisclosed endowment to the Smithsonian to purchase the ring, which experts say is worth millions.