Emerald is the clear, green-hued form of the mineral beryllium and is valued as a precious gem. The green coloring of emeralds makes them popular for use in gold jewelry for accenting the tone of the metal. An important aspect of emerald-handling is knowing whether the emerald that you have is authentic or not. While an expert should always be consulted on final authentication matters, there are a few methods of home-authentication that you can try before heading out to a gemologist.
Clean the emerald thoroughly with a cleaning cloth to remove any surface dirt or residue. Marks on the stone can prevent proper identification so make sure to remove even thumbprints. Hold the stone in a pair of tweezers to keep the emerald clean.
Move the emerald under a strong light and adjust the stone so you can reflect the light. Hold a white card near the stone to bounce the reflected light off and look for refractions of the light in the stone. If the light refracts onto the back of the gem, it is certainly not glass or acrylic and likely genuine.
Check the light that the stone emits for coloring and hue. A genuine emerald produces a rich green glow when light passes through it because of the natural impurities that develops in the mineral. Glass, crystal and acrylic are void of these impurities and cast a nearly clean light.
Inspect the edges of the stone for en exposed or pointed edge and run a file gently against it. If the file moves smoothly and easily across the stone, it is real. A fake stone will cause roughness and abrasions from the file.
Hold the stone under the lens of a binocular microscope and look at the stone's appearance thoroughly for signs of feathered inclusions. Inclusions are imperfections within the emerald in the form of slight cracks, crystallization or growth lines. These inclusions occur in authentic emeralds and are difficult to reproduce accurately.
Never purchase an emerald or any precious stone without seeing your dealer's certification for distributing authentic gems.