In 1907 Bertram Goodhue built a townhouse at 106 East 74th Street (demolished
in the 1920's) with a Gothic/Tudor front.   The main facade is dominated by
leaded glass windows set in bays, Tudor style, but historic photographs reveal
no more.

In 1916 House Beautiful wrote "the triple window is leaded with diamond
quarries."

What might "diamond quarries" mean in such a usage?

Christopher