朱沙 / 朱砂

しゅさ

RELATIONどう関係するか

Cinnabar/vermilion is the mineral basis of 朱色; period texts call both natural and synthetic forms shu/shusa.

BASIS出典の根拠

Tobunken's 彩色DB records 朱沙/朱砂 (cinnabar, HgS) with Shōsōin-document citations.

CAVEAT境界

Mineral pigment context only; grinding fineness shifts the hue, so no single HEX is authoritative.