Antique Engagement Ring Art Deco GIA .92 Old European Cut Diamond in PlatinumIts all in the details when it comes to Art Deco era rings, and this one left no detail unfinished. Down the the delicate engraving on the prongs of the box set . 92 carat Old European cut diamond, to the intricate geometric shapes that make up the setting and the engraved detailing down the band this platinum ring has it all.