Pique-nique 16,23 oz Verre d'ouragan en cristal sans plomb (Ensemble de 2)

I love these glasses. Perfect for a margarita. However, they very fragile. One broke on first use simply by plopping an ice cube into the glass. The corner of the ice cube punctured a dime sized hole in the bowl. I tried to take a photo, but impossible to see. Very unsatisfactory for what I consider an expensive picnic glass. I expected something more sturdy. Who would think an ice cube would break a glass?