The Stones Unturned Add-on for Mafia III: Definitive Edition has 10 achievements worth 320 gamerscore.
Kill 50 enemies using the Hartmann 7.62mm and wearing the Party Animal outfit
Knock out 30 people with the Dart Gun
Complete all Bounty Hunting assignments
Place an unconscious person in the trunk of a car
Complete "There Are No Dominos"
Eliminate a traitor
Complete "Big Money"
Complete "Devotchka"
Complete "Creature of Habit"
Kill 30 Enemies Using Sniper Support