Algarum thread

Algarum thread is used along with sirenic scales to make sirenic armour. It can be bought from Ocellus Virius, or on the Grand Exchange. Three of these are needed to make a sirenic hauberk, two to make sirenic chaps, and one to make a sirenic mask.

The shop interface to buy these from Ocellus cannot be opened without at least in the money pouch or inventory.

Trivia

 * If zoomed in on when dropped, it can be seen that this thread has an animated pattern on its surface.
 * According to Ocellus, the Order of Ascension stole the thread to make armour, and then he stole the thread from them to prevent them from making armour.