Prev's Magnificent Materials — Mithril

Mithril is an ore that generates in stone, deepslate and possibly netherrack, and it is rare. Its tools and armor compare favorably to diamond on several properties: they are enchantable, tools wear out faster, and armor lasts longer. Horse armor is included in the set.

Prev's Magnificent Materials is meant to add new metals, alloys and other materials to vanilla Minecraft, and the author describes it as a base other content can build on. Armor sets for materials such as bone are modeled in Blockbench. A Samurai armor set is in progress and is used to make Samurai variants, with a helmet, called kabuto, already finished.

Geckolib is required, because the custom armor models depend on it, so the matching GeckoLib version has to be installed. Installation covers the server and each player's game. Files are published for Forge only, for 1.19.2. The mod is not open source; it is released under All rights reserved, and its source code and issue tracker are public.