\Cach"o*long\, n. [F. cacholong, said to be from Cach,
the name of a river in Bucharia + cholon, a Calmuck word for
stone; or fr. a Calmuck word meaning ``beautiful stone'']
(Min.)
An opaque or milk-white chalcedony, a variety of quartz;
also, a similar variety of opal.