poecilitic

from The Century Dictionary.

• noun A name suggested by Conybeare as an equivalent for New Red Sandstone, in allusion to its variegated color, the rocks of which this group is made up consisting chiefly of red, yellow, and variegated sandstones, conglomerates, and marls, with occasional beds of limestone. See sandstone, Permian, and New Red Sandstone (under sandstone).
• noun In petrography, a term used by G. H. Williams in 1886 (in the form poikilitic) to designate the texture of those igneous rocks in which comparatively large crystals act as a matrix for many smaller ones, which are included in the larger ones, and, when these are cleavable, produce luster-mottling.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Mottled with various colors; variegated; spotted; -- said of certain rocks.
• adjective Specifically: Of or pertaining to, or characterizing, Triassic and Permian sandstones of red and other colors.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective geology Mottled with various colours; variegated; spotted.
• adjective geology, specifically Of or relating to, or characterizing, Triassic and Permian sandstones of red and other colours.