What is elementless jewel?

Elementless jewel is a type of jewel in the game Monster Hunter World that provides a skill called Non-Elemental Boost. This skill increases the attack power of weapons that do not have an elemental attribute by a certain percentage. Elementless jewel can be obtained by completing various quests or through melding at the Elder Melder. The jewel can be slotted into weapons with a level 2 or higher decoration slot. It is particularly useful for high damage weapons such as greatswords or hammers, which often do not have elemental damage. Maxing out the Non-Elemental Boost skill requires equipping multiple Elementless jewels.