Webster's Revised Unabridged Dictionary · 1913

Macle

Macle , noun

[Latin macula a spot: compare French macle. Compare Mackle, Mascle.]

(a)
(Mineralogy) Chiastolite; -- so called from the tessellated appearance of a cross section. See Chiastolite.
(b)
(Mineralogy) A crystal having a similar tessellated appearance.
(c)
(Mineralogy) A twin crystal.