The Auria Stones

The Auria Stones are the most powerful magical objects known to spellcasters. These seven stones appear throughout history as sacred objects wielded by the few Sorai lucky enough to carry one. The stones only react to Sorai magic, lighting up with white markings that resemble the same white marks all Sorai are born with.

No one is quite sure what kind of effect the stones have on a Sorai's magic, or if they have an effect at all. Some say the stones boost a Sorai's magic, making it even stronger. Some argue the stones act more like wands or staffs and stabilize magic to help a Sorai control their magic. And some believe the stones have a negative effect and any Sorai carrying one will be driven mad.

Tracking the stones exact histories can be tricky. The stones disappear and reappear through history seemingly at random, often vanishing for centuries at a time before being seen again. Part of this is believed to be the descendants of past Sorai keeping the stones as heirlooms to pass down through the family line.
Sometimes a family will claim they have an Auria Stone, only to be proven wrong when they gift said stone to a Sorai and nothing happens.
What is far more common, if a family does posses an Auria Stone as an heirloom, is the family keeping it a closely guarded secret.

The other part that makes tracking the stones tricky is that not all Sorai disclose when they carry an Auria Stone. Thus there is no way to know exactly how many Sorai have wielded one.

The seven stones are;
Dawn (destroyed)
Twilight (broken)
Midnight (destroyed)
Meadow (missing)
Prism (missing)
Casem (destroyed)
Ocean (missing)