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