Chiastolite
Pronunciation : Chi*as"to*lite
Part of Speech : n.
Etymology : [Gr. -lite. See Chiasm. So called from the resemblance of the cross cuts of is crystals to the Greek letter x.] (Min.)
Definition : Defn: A variety of andalusite; -- called also macle. The tesselated apperance of a cross section is due to the symmetrical arrangement of impurities in the crystal.
Source : Webster's Unabridged Dictionary, 1913