HiyaHiya Nirvana Bone Crochet Hooks Length: 6" / 15 cm. Bone Crochet Hooks are exquisitely smooth, with a highly polished, almost glass-like finish. Please note: There is a natural variation in bone color and we are unable to send a color preference. Bone ranges in color from off-white to ivory. Bone is susceptible to shock and may break if dropped on a hard surface; use caution to avoid dropping them.