A few Fenton pieces were made from the non-opaque and non-iridescent depression glass as well. Fenton also produced a limited number of items in opalescent glass.
There are a number online forums and Fenton collector's club websites where you can upload pictures and/or descriptions about a particular piece, and avail the help of the members for ascertaining its authenticity.
Though you might not find those rare ones, Fenton glassware bought from any one of these stores is guaranteed to be genuine. Over its more than a century long run, the company has produced thousands of beautiful glassware, having innovative colors and striking hand-painted decorations.
In 2011, the company officially ceased traditional glass-making, and now makes only glass jewelry items.
Barring the exception of a few very rare off-hand glass items made by them in the 1920s, a majority of Fenton pieces do not sport a pontil mark.
One could also make use of the Fenton catalogs available in the 'For Collectors' section of the Fenton Art Glass Website.
Many Fenton pieces have special markings, stickers, or logos on them, which can serve as a good means for identification.
Some pieces that were sold exclusively from the Fenton Gift Shop included markings of a solid star, an open star or the letter "F".
Two 1995 historic Fenton collections - Lotus Mist and Willow Green Opalescent received a circular marking with '95' inscribed within it, in the year 2000.