A gemstone, a variety of zircon that was believed to protect
the wearer from plague and from lightning, to strengthen the
heart, and to bring wealth, honor, prudence, and wisdom. It
was recommended by Albertus Magnus as a soporific on account
of its coldness and was ordered by Psellus in cases of
coughs, ruptures, and melancholy; it was to be drunk in vinegar.
Marbodeus described the wonderful properties of three
species of jacinth. Pliny and Leonardus also spoke highly of it.