Amulet of Spell Empowerment

This amulet of strange ferric ore has runes carved on its surface. The amulet has 7 charges and regains 1d6+1 charges daily at dawn. If you expend the last charge, roll a d20. On a 1, the amulet turns to dust and is destroyed and the caster loses 7 spell levels of his/her choice.

While attuned to the amulet, when you cast a spell that can be cast at higher levels, you may expend any number of charges to cast the spell at a level higher than the base level by the number of charges expended. The spell slot expended is that of the base spell level. The amulet cannot allow casting the spell at a higher level than the caster's maximum spell slot.

Notes: Set: Constitution Score, Requires attunement by a spellcaster, Buff, Jewelry