This series currently has two weapons – Lithic Blade and Lithic Spear. They both have an ATK secondary stat and share the same passive. The passive is called Lithic Axiom – Unity. At Refinement Rank 1 (R1), it has the following effects:

For every character in the party who hails from Liyue, the wielder gains 7% CRIT ATK and 3% CRIT rate. This can stack up to 4 times. At R5, each stack can buff 11% ATK and 7% CRIT rate.

This is a really strong passive that just gets better with more stacks and refinements. But it can be restricting to adjust your team comps for its passive. There are simply plenty of strong non-Liyue characters that are valuable in their teams. As such, Lithic weapons can just be considered a stat stick that offers a lot of ATK and occasionally CRIT rate. Its passive buffs are just bonuses you get when a Liyue teammate joins the team – not something you actively seek. Here’s a summary of their synergies with every current polearm and claymore user.

Great means that it’s among the character’s best 4-star weapons. Good means that it works well on the character, but they have other better 4-star options. Not recommended means that the unit has significantly better weapon options or doesn’t synergize with the weapon.