… sometimes set with precious stones. It's a nonessential participle phrase. A comma is used because it's not part of the main clause and doesn't add information necessary to the meaning of the sentence.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
addyaddyPlease tell me how to reconstruct the first sentence with out the commaWomen like to wear expensive gold jewellery that is sometimes set with precious stones.