A variety of
ChalcedonyA microgranular or microfibrous form of chalcedony coloured in various shades of green by disseminated silicate particles (variously attributed to celadonite, chlorite, amphibole, etc).
Various descriptions of Plasma include: as:
of a dullish green color with yellow and whitish dots and a glistening lustre
J.D.Dana (1837)
Its most common colour is a variety intermediate between grass green and leek green and sometimes approaching to pale mountain green It frequently occurs greenish white and oehre yellow the latter colour is in dots the first in spots or clouded Internally its lustre is glistening inclining to glimmering.
R.Jameson (1816)
Compare with
Prase, which has a very much more defined colour ("leek green") and is generally more translucent.
