Dark Blue Polka Dot Hobnail Japanese Cast Iron Tea Cup Teacup ~ We Pay Your Sales Tax his high quality blue cast iron teacup is perfect for enjoying tea. It can also serve as a great companion for any cast iron teapots (tetsubin). Size 3.2'' (L) x 2.2'' (H) This classical Japanese style teacup is made from sturdy iron and has blue enamel coating on the interior to prevent rusting. Japanese cast ironware heats evenly and retains heat well and is praised worldwide for their beauty, strength, and superb quality. Cast iron is strong and will not break! You'll find that a cast iron tea cup when properly cared for, will last you a lifetime!