Porcelain has been described as being "completely vitrified, hard, impermeable, white or artificially coloured, translucent, and resonant". However, the term "porcelain" lacks a universal definition and has "been applied in an unsystematic fashion to substances of diverse kinds which have only certain surface-qualities in common". Traditionally, East Asia only classifies pottery into low-fired wares and high-fired wares, the latter also including what Europeans call stoneware, which is high-fire