How can you tell if a star sapphire is natural?

One way to tell if a star sapphire is natural is to shine a flashlight on it while in total darkness. On a genuine star sapphire, the light that reflects off of the stone will be the same color as the stone. Glass and other materials used to create synthetic stones may show reflections in different colors. To be certain of the authenticity of a gemstone, take it to an experienced jeweler or appraiser for an evaluation. On 1stDibs, find a selection of star sapphire jewelry.