Magic stone

Magic stones are marble-like magical objects found inside monsters and particularly high-ranking individuals. They act as physical containers of mana and magic. They are extremely precious, with a C-rank magic stone costing as much as 10 million won.

Appearance
In the novel, magic stones are round stones, not unlike gemstones. In the webtoon, magic stones are irregularly-shaped crystalline formations. Their size varies depending on the grade of the monster they come from, ranging between pebble-sized to as big as a small child's head. The rank may also have an effect on the size, with higher-ranked stones more likely to be bigger. The largest known stone is a high-grade L-rank, and S-rank stones are big enough to cut business cards out of.

Magic stones are colored differently depending on their rank:


 * C-rank: Red
 * A-rank: Silver
 * SS-rank: White (opaque)
 * L-rank: Varying colors; possibly dependent on the creature they come from. Known examples include clear/transparent and murky black

Origin
Magic stones are crystals containing the power of the source. Their appearance in a world marks it as ready for absorption by the source. They appear naturally in monsters, as well as in non-monster lifeforms that have grown past a certain threshold of strength. In humans, magic stones appear when they reach SS-rank, as a marker that they have grown past the physical limit of their species.

Usage
Magic stones can be used as fuel for a variety of things, most commonly items. Aside from fueling things, they can form magical objects in and of themselves.

Magic stones can be used in their entirety or in parts. It has been shown to be possible for small shavings of a magic stone to power an item such as the Shalos' Bead. Smaller pieces can also be attuned to work as items, such as the mini portal access keys for Han Yoojin's residence, which are made from thinly-cut slices of an S-rank magic stone.