Crystals are found in the Nether, and these crystals can be mined to create enchanted leather armour.
In Minecraft, tears of crystal are collected by players for enchanting items or brewing potions. Failing to collect these tears will cause them to disappear from an area. The biggest advantage of collecting the obsidian over other blocks is that it does not have a level cap- you can put whatever number you want when selecting what enchantment level, so all levels become available eventually which it is most useful for enchanting tools and armor because the rarer levels are easier to obtain than with ordinary stone blocks at lower levels but also require more experience on your part at higher ones. Crystals’ other use is as a debuff barrier if there are plenty of them scattered about, as they can be mined and replaced quickly. Crystals benefit a large number of the players because it makes the enchanting process much easier due to having all levels available rather than just four or five.