For the Boar Tusk Talisman in RDR2, you need 3 materials, all of them being quite accessible, as you can see below.
This specific talisman affects your horse’s Stamina and Health Cores, thus the animal will be able to sprint for longer distances.
Boar Tusk Talisman Materials:
1x Gold Earring – You can find it inside the drawer of a nightstand while playing the Watson’s Cabin home robbery. You can also get more by robbing trains, in case you sold the RDR2 Gold Earring in the cabin.
How to Craft the Boar Tusk Talisman:
As with all talismans, take the materials to a Fence and pay the shopkeeper the amount of money he asks.
How to Use the Boar Tusk Talisman:
The Boar Tusk Talisman is a very useful item. It slows down by 10% the draining speed of your horse’s Health and Stamina Cores. Keep it in your inventory during your journeys. Even if you don’t equip it, its bonuses remain active.