A federal judge Wednesday tentatively approved a $6.7 million settlement in a lawsuit brought on behalf of customers and salespeople who allege they were left in the lurch when a jewelry company abruptly ceased its direct-sales operations.In a hearing, U.S. District Judge Samuel Der-Yeghiayan granted a motion for preliminary approval of the settlement reached between three classes of plaintiffs and Wood Dale-based costume jewelry company Lia Sophia.The settlement fund would contain an estimated $3,575,000 to provide relief …