Fenton Art Glass also owes its early success to famous glass chemist Jacob Rosenthal, also known as Uncle Jake, whose glass career began shortly after the Civil War. Perhaps Rosenthal's most important contribution to the young company was his role in the creation of iridescent glass, known as carnival glass, which Fenton introduced in 1907, Rosenthal's carnival glass, chocolate glass (sometimes called caramel glass by antique dealers), and golden agate pieces are now much-sought-after collector's items. Rosenthal also helped the company persuade other talented glass workers to relocate to Williamstown.
