A proper visual inspection (and a search for impurities) is one of the most efficient ways to tell if a ruby is real. This method can be dramatically aided by the use of a 10x magnifying glass. Examine the gemstone in a well-lit area against a solid backdrop, like a plain sheet of paper or an untextured cloth. Some minor impurities may be visible within an authentic ruby, but beware of flaws like inconsistent coloration, tiny bubbles, or unnatural marks either on or within the stone. Another red flag is when a stone appears to be “too perfect,” which means that the ruby is likely a glass composite.
Finally, if you suspect that your ruby may be fake, seek out a certified second opinion at your local jeweler.
This article was published at an earlier date and has since been updated.