GEM OF A DEFINITION

Sylvia Bursztyn and I appreciate Kate Reeves’ distinction between opalescence and chatoyancy in regard to our cluing “cat’s-eye” as “opalescent gem” in our Dec. 8 Puzzler (Letters, Dec. 15).

But not being mineralogists, we relied on the Merriam-Webster’s Collegiate Dictionary (10th edition) definition of “cat’s-eye”: “Any of various gems (as a chrysoberyl or a chalcedony) exhibiting opalescent reflections from within.”

BARRY TUNICK

Culver City