The New International Encyclopædia/Chiastolite

CHIASTOLITE, kī̇-ăs′tō̇-līt (from Gk. χιαστός, chiastos, diagonal, from χιάζειν, chiazein, to yawn, from χῖ, chi, name of the twenty-second letter of the Greek alphabet + λίθος, lithos, stone). A dark-colored variety of andalusite, consisting of stout crystals which, owing to a regular arrangement of carbonaceous impurities through the interior, show in cross-section a colored cross. This mineral is found in Andalusia, Spain, in Tyrol, in Saxony, in Austria, and elsewhere in Europe, where it is frequently sold as a gem, and, owing to the cross-like appearance, is prized, especially among the lower classes. In the United States the best chiastolites are found in Lancaster and Westford, Mass., and especially in Mariposa County, Cal.