the world > the earth > minerals > types of mineral > silicates > tectosilicate > [noun] > quartz > cryptocrystalline quartz > chalcedony > onyx > varieties (3)
An onyx stone partaking of the characters of jasper; ‘an old name for clouded jasper’ (A. H. Chester).
onyx with parallel opaque and translucent layers.
A black or brown variety of onyx with a thin bluish-white vein, used esp. in cameos and intaglios.