How can I tell if my blue diamond is real?

To tell if your blue diamond is real, look for a maker's mark on your piece. By researching the manufacturer using trusted online resources, you can find out if the jewelry maker tends to use authentic gemstones or rhinestones in its pieces. If you can't find a mark or are still uncertain, consult a certified appraiser or knowledgeable jeweler. Performing home tests for diamond authenticity can damage your jewelry, so getting a professional opinion is often the best way to protect your piece. Find a range of blue diamond jewelry on 1stDibs.