From V Rising Wiki
Jewelry
Jewelries in V Rising are equipable items that can provide stat boosts. Jewelries must be placed in a character's jewelry slot to work. As tiers progress in jewelry the bonuses increase and get stronger. Jewelries can be crafted at Jewelcrafting Table and Simple Workbench, this is currently only way to obtain them.
In addition, you need to unlock Jewelries to be able to craft them. This is possible through killing V Blood Bosses and through blueprint system.
By slotting different Jewelry at your hot bar you can quickly change them for different type of boosts. This is particularly useful in duels with other players.