Refers to the opaque, fine-grained variety of quartz used as a gemstone or ornamental stone.
碧玉は古代から印章や装飾品に使われてきた。
Jasper has been used for seals and ornaments since ancient times.
yellow jasper; beryl
From Chinese 碧玉 (bìyù), literally 'green jade', though in modern mineralogy it refers specifically to jasper.