Gouge. Melee Weapon Attack: your spell attack modifier to hit, Reach 5ft., one target. Hit: 8 (1d8 + 2 + PB) bludgeoning damage.
Glittering Topaz (Recharge 5-6). Topaz Carbuncle increases its AC by 2 for 1d4 rounds.
Shining Topaz (Recharge 6). Melee Magic Attack: your spell attack modifier to hit, Reach 5ft., one target. Hit: 8 (1d6 + 2 + PB) bludgeoning damage. A creature struck by Gouge must make a Wisdom saving throw against your spell save DC. On a failed save, the creature has disadvantage on actions taken against targets other than the Topaz Carbuncle during their next action.