18k yellow gold. I purchased it a bit over a year ago but I’m just not a jewelry person and I wore it maybe a few times. It’s in great condition. I didn’t wash my hands in it or anything. From Tiffany’s website: Description & Details Tiffany Knot is an expression of love’s unwavering bonds. Inspired by an archival bow crafted in 1889, Knot is a symbol of life’s most enduring ties and meaningful connections. This ring is crafted with yellow gold and polished by hand for high shine. Wear on its own or partnered with classic silhouettes for an unexpected pairing.