How can you tell real onyx from fake?

Real onyx can be identified by its unique banding patterns, which are often smooth and consistent, while fake onyx may have unnatural or overly uniform designs. Additionally, real onyx is usually heavier than its synthetic counterparts, and it can feel cool to the touch. You can also test its hardness; genuine onyx scratches less easily than plastic fakes. Lastly, observing the stone under a light source can reveal the depth of color and translucence typical of real onyx.