Hyphens, En Dashes, Em Dashes

Q. Let’s say you have a phrasal adjective that includes an open or hyphenated compound, the word and, and an attributive noun, such as “sterling silver and diamond.” When placing this phrasal adjective before a noun (such as brooch), how would you use en dashes or hyphens? Would it be “sterling-silver–and-diamond brooch” or “sterling silver–and-diamond brooch” or something else? I would like to do “brooch of sterling silver and diamonds,” but that won’t fly with the fashion editors where I work.

A. Use no punctuation if the meaning is clear without it, or use simple hyphens (sterling-silver-and-diamond brooch) if otherwise it might look like two items: sterling silver, and a diamond brooch. In a paragraph or catalog about brooches, you are probably safe without punctuation. Reordering the items might help. When you’re tempted to use one hyphen and one en dash or use two en dashes, you are almost certainly overthinking and about to produce something monstrous.

[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]