According to Official Guinness Records,
The most diamonds set on a lipstick case is 2,216 diamonds and was achieved by Aaron Shum Jewelry Ltd (Hong Kong), in Hong Kong, China, as verified on 22 September 2018.The company was previously also awarded the record for the most diamonds set on a handbag and most jewels on a guitar.
For a complete list of 2018 records, please visit 2018 Guinness Records in China.