
1) Opal
Found on
https://www.crosswordclues.com/clue/cacholong

Cacholong, also known as Kalmuck Agate, is a form of common opal, although it is often mistaken for agate or chalcedony. A milky white colour with a Mohs hardness of about 6, it is used for carving, cameos, etc. Found in Austria, Czech Republic, Mongolia and Uzbekistan, its name possibly comes from a river in Uzbekistan. ...
Found on
http://en.wikipedia.org/wiki/Cacholong

• (n.) An opaque or milk-white chalcedony, a variety of quartz; also, a similar variety of opal.
Found on
http://thinkexist.com/dictionary/meaning/cacholong/
Cach'o·long noun [ French
cacholong , said to be from
Cach , the name of a river in Bucharia +
cholon , a Calmuck word for
stone ; or from a Calmuck word meaning 'beautiful stone']
(Min.) An opaque or milk-white chalcedony, a variety of quartz; also, a similar variet...
Found on
http://www.encyclo.co.uk/webster/C/3

Cacholong or mother-of-pear opal and sometimes Kalmuck agate, is a variety of opal, usually grey in colour, milk white or bluish white, and resembling mother-of-pearl. It is banded with layers of different colours and is a most attractive ornamental stone.
Found on
http://www.probertencyclopaedia.com/browse/HC.HTM
No exact match found.