The stone is a magenta-colored jewel with a tear-shaped structure. Its surface is decorated with yellow trim-lines and has the initials "JP" in a stylized yellow font. The stone is worn as a necklace with a simple string tied to it.
The stone came from a faraway region overseas, where it was bought by Airi's father as a souvenir for his daughter.
The stone's most distinct feature is that it gives the ability to power up a Jewelpet's magical abilities. If the wearer's bond with the Jewelpet is strong, it will glow and react with the Jewelpet's magical items. On contact, the stone's magic will combine with the Jewelpet's magical powers and augment them. If the Jewelpet is far from the wearer, the stone will emit a magical orb where it can travel towards its target. After being infused with the stone's magic, the Jewelpet will take on a humanoid appearance and, at the same time, power up their magical abilities.
It is possible to force the Magical Stone to produce its magic-amplifying power through manual action. A Jewelpet can use their own magic to directly amplify the stone to make it produce its magic-amplifying magic. But depending on how much effort a Jewelpet puts into amplifying the stone, the magic produced may become faulty, and upon fusion the Jewelpet would only be granted with a menial boost of magic and their humanoid transformations will be less appealing (such as Larimar turning into an elderly lady).