Question: are riedel wine glasses crystal?
Answer: The more costly series of Riedel, such as the Sommelier, Vitis, Vinum, Vinum Extreme, and Vinum XL and the Wine series are made of crystal. The Sommelier Series are all handcrafted and mouth-blown crystal from Austria. ... To achieve the same brilliance and luster of the lead crystal, they opted borosilicate.