Ru kiln porcelain, also known as "agate glaze porcelain", uses precious agate in the glaze, with a unique color and is known as "like jade but not jade, but better than jade". Ru kiln porcelain has a fine and hard body, a moist and bright glaze, and small cracks on the glaze surface, commonly known as "crab claw pattern". Ru kiln porcelain has a simple and elegant shape, and the most precious glaze colors are sky blue, powder blue, and moon white. The firing process of Ru kiln porcelain is complicated, and the output is very small. There are only more than a hundred pieces of Ru kiln porcelain handed down from generation to generation, so Ru kiln porcelain is known as the "treasure among porcelains