noun
ironstone china
A type of hard, durable pottery; a technical term used in ceramics and tableware contexts.
このカップは硬質陶器でできているので、割れにくい。
This cup is made of ironstone china, so it's hard to break.
陶器 is a general term for pottery or earthenware, while 硬質陶器 specifically refers to ironstone china, a harder and more durable type.
Compound of 硬質 (hard, rigid) and 陶器 (pottery, ceramics). The term is a direct translation of the English 'ironstone china'.