油あぶら石いし

noun

oil stone; stone with an oily luster

Refers to a type of stone that has a natural oily or greasy sheen, often used in decorative or lapidary contexts.

• この油あぶら石いしは磨みがくと美うつくしい光こう沢たくが出でる。

  This oil stone develops a beautiful luster when polished.

noun

coal; charcoal

An older or regional term for coal or charcoal, likely from the resemblance to an oily stone. Not the common modern word for coal (石炭).