0 0 0 0 0 0 0 0 7103.99 Precious and semi-precious stones, worked, whether or not graded, but not strung, mounted or set, precious and semi-precious stones, worked, ungraded, temporarily strung for convenience of transport (excl. precious and semi-precious stones, simply sawn orr roughly shaped, diamonds, rubies, sapphires and emeralds, imitation precious stones and semi-precious stones) 50