This is a handmade mug by Christine Sakos, made in Bucks County, PA. It was thrown on the wheel using stoneware clay and then altered by hand to add a swirl design and embedded Quartz Crystal thumb rest. The glaze is lovely blues with purple and white. Food safe. Hand-wash only, and due the Crystal you should not use this in the dishwasher, oven, or microwave. Enjoy this beautiful treasure, sure to delight anyone as they sip from this enchanting mug!