The term 'Big Name in Diamonds' can be summarized by two crossword solutions: Zales (5 letters) and DeBeers (7 letters). Zales is a jewelry retailer founded in 1924 in Wichita Falls, Texas. It is now the largest specialty jewelry chain in the United States. DeBeers is a diamond mining company founded in 1888 by Cecil Rhodes. It is one of the world's largest diamond producers and has been a major player in the diamond industry for over a century.