The Jeweled Candlestick is a decorative item, and serves as one of the Thieves Guild Trophies. This item will show up on the top shelf of the right bookcase behind the Guild Master's desk in the Thieves Guild headquarters, along with any collected larceny targets. It seems to appear after doing five jobs for Vex and Delvin. It appears you can not take the trophy items from doing a set amount of jobs, but can take the ones you find and sell to Delvin.