Blue Nile cuts 50% off select diamond jewelry via coupon code "FRIDAY15" during its Black Friday Sale. Plus, all orders qualify for free shipping. That's the best discount we've seen on diamond jewelry from Blue Nile. Rings start at $490, earrings start at $1,325, and bracelets start at $2,999 after discount. Deal ends November 29.

See all Blue Nile Coupons.