Lajvardina, from the Persian word for lapis lazuli, was a style of pottery made under the Ilkhanid dynasty in the 13th and 14th centuries. It was fritware, with ground glass in the paste. It was fired twice, the first time with a solid cobalt or turquoise glaze, and a second time after it had been decorated. I love it. The bowl above is in the Louvre, which has a wonderful collection.