Mox by StarSailGames

Mox

A mox is an arcane gemstone associated with a particular type of magic determined by its material. Mages can tap
into the mox's power to boost the potency of a spell associated with its kind of magic.
Moxes were originally created by wizards to aid students specializing in particular schools of magic. But, they are
now used by spellcasters of various backgrounds who
wish to focus their abilities on specific types of magic.

Mox

Wonderous item, uncommon (requires attunement)

This gem contains power associated with a specific
school of magic and can empower spells from that school. When you cast a spell from the school of magic associated with the gem, you may use the gem to empower the spell, causing it to be cast at one level higher. The gem can't be used this way again until the next dawn.

The mox's material determines what school of magic it
is associated with.

Amber - Conjuration

Jet - Necromancy

Ruby - Evocation

Pearl - Abjuration

Chrome - Transmutation

Opal - Divination

Emerald - Enchantment

Sapphire - Illusion