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
Complete all Bounty Hunting assignments
Knock out 30 people with the Dart Gun
Complete "There Are No Dominos"
Eliminate a traitor
Complete "Big Money"
Complete "Devotchka"
Kill 30 Enemies Using Sniper Support
Complete "Creature of Habit"
Place an unconscious person in the trunk of a car