Heiseikōseki

A Heiseikōseki (こうせきへいせい, serenity crystal) is a naturally, synthetically, or artifically crystallization of Reishi or Reiryoku into a spiritual crystal and other mineral like stones and glass. These stones due to being creation from spiritual substances possess unique powers.

Overview
These gemstones, glasses in nature, and other mineral stones can be formed naturally, synthetically, and artifically. For naturally formed Heiseikōseki to occur take years, like how crystals in the World of the Living are formed. Except, these are formed from natural Reishi or Reiryoku. The type of crystal, glass, or stone mineral that is formed is depended upon on two actors. What minerals the reishi in a spiritual world is combined with in the natural crystallization. Also, which spiritual world is a factor. For each different world or unique space in that world, has a different properties mixed with the surrounding reishi.

Natural Formations of Heiseikōseki
The most powerful, rare, and valuable of all Heiseikōseki are the natural ones. They are formed from minerals in any spirit realm, that combines with the surrounding reishi or reiryoku.

Historical Information
When, the exact date the Heiseikōseki was discovered is been lost for centuries. Mushoku Kaigan one of the Panteon's Shuhan's is the last one to unlock its secrets though. However, Mushoku states that Heiseikōseki are beyond old, but are just another natural type of crystallization found in the spiritual worlds and rarely the World of the Living.

Abilities & Powers
Unique Reiryoku Powers and Properties: All Heiseikōseki possess spirit energy. The strength of these powers are determined by the amount of reishi that is fused with the minerals. Also, due to minerals fusing with the surrounding reishi the Heiseikōseki can inherit any special properties the reishi has. For example, natural Heiseikōseki formed in the Panteon a separate space in the Soul Society can possess Choujouteki Sadame (超常的定め, Supernatual Law) which is a spiritual property that affects and penetrates Sekkiseki and Gekitai (黄泉撃退, Underworld Repel) which mean the Heiseikōseki are effective against spiritual beings from Hell. Heiseikōseki formed in Hueco Mundo, can gain properties that can devour a spiritual being's entirety.

Sharpness/Hardness: Heiseikōseki due, to being spiritually charged increases the hardness of the Heiseikōseki. It has been known that certain Heiseikōseki can have spiritually charged sharpness or hardness enough to break a Captain-level Bankai released Zanapkuto or even penetrate a wall of Sekkiseki without the required properties.

Glowing Aspects: A Heiseikōseki due to have spiritual powers, can emit a glow of spiritual light. While, more normal or less powerful will only emit a glow while they are used. Some more powerful and or rare can emit light endlessly.

Visible: Since, the World of the Living has a small degree of Reishi in the atomosphere Heiseikōseki do exist in the living world. Since the minerals in the World of the Living are visible these crystals formed naturally or overwise are visible. However, none spiritual aware humans cannot use their powers or see any spiritural light from them (adept they are rare exceptions to this).

Weaponary and Items
Kōteikōsekiyari (皇帝こうせきやり, emperor crystal spear): Is an ancient, divine, and powerful spear fashioned with many Heiseikōseki and the blade of spear is made Heiseikōseki.