Droconites, otherwise dentrites draconius, or obsianus, is described by Albertus Magnus as a shining black stone of pyramidal figure.
It is difficult to obtain, as it must be taken from the head of a dragon, cut off while the beast is still panting. It subdues all kinds of poison, and gives its possessor invincible courage. The kings of the East esteemed it as a great treasure. A.G.H.
Source: 81, 130.