The crystal saw (Prifddinas) is a degradable saw that is made by Crystal Singing with a crystal tool seed and 150 harmonic dust. This requires 80 Smithing and gives 300 Smithing experience. Alternatively, you can pay Ilfeen, Eluned, Islwyn or Rhodri Dail 1,500 - 7,500 coins to turn a crystal tool seed into a crystal saw, without any harmonic dust or 80 Smithing.
When equipped, the saw gives a hidden 5 level boost to Construction that lets you build furniture five levels higher than you would normally be able to. This advantage is not applicable when constructing things that do not require a saw, such as monsters, plants, or rooms. This bonus is stackable with drinking teas and spicy stews that already boost this skill, only for objects requiring a saw to make. As the saw needs to be equipped to be effective, the sculpting chisel does not stack with it.
If a player has both a normal saw and a crystal saw in their inventory when building furniture, the crystal saw will be used and a charge will be deducted, even if the player has the requisite Construction level for the piece of furniture and does not need the crystal saw's boost.
Each use consumes 3.57% charge so once it has been used to build 28 things, it will degrade into a crystal tool seed. Like other crystal items, the degrade rate is halved in Prifddinas, however there is no way to use this item within the elven city. (Houses located in Prifddinas will not benefit from this). The tool seed can be recharged by Ilfeen, Eluned, Islwyn or Rhodri Dail for a cost that starts at 7,500 coins but decreases by 1,500 every enchant, to a minimum of 1,500 coins.
Enchantment
Cost for re-enchantment
First
7,500
Second
6,000
Third
4,500
Fourth
3,000
Fifth and thereafter
1,500
You can also talk to Ilfeen, Eluned, Islwyn or Rhodri Dail if you want to turn your saw back into a seed.