Notice the shading. Amberina glass is heat-sensitive and is reintroduced into the heat before it has cooled. Because of the this, the top portion of the bowl vase will be a bright and rich red, then fade to amber throughout the base of the bowl. A vase that is solid red, orange or amber is not a true amberina vase.
Note the specific shade of red in the glass. As with old stained glass, the color red made for amberina vases is paired with gold. This gold melted within the glass will give it a deep red-orange color. Because this method of creating red glass can be quite costly, many modern glass companies will use iron, and sometimes selenium. Although this may look like true amberina glass, you'll notice a brighter yellow tint to the glass rather than red/orange.
Look for chipping of the color. A true amberina or gold ruby glass vase's color will be completely smooth throughout the vase, and will not chip or wear away over time.
Research the glassmakers. The largest glassmakers of amberina glass were Gillinder & Sons, Hobbs Brockunier and Co., New England Glassworks and The Libbey Glass Co. Take your glass to a specialist or appraiser, who will be able to determine where and when the glass was made.
Examine the bottom of the glass. True amberina glass is blown. When glass is blown, rather than cast, there will be a small marking or hole in the center of the base of the vase. If you're vase has an actual seam through the sides of the vase, it is not amberina.