I've seen similar pieces attributed to Erik Hoglund, a designer at Kosta Boda. It was through this experience that he mastered his craft and gained the knowledge to start his own factory. After cooling to a temperature of 1200°C (2190°F), a piece is soft enough to be worked.

Origin: Mexico
Pattern: Vintage
Shape: Face
Color: Purple
Material: Glass
Subject: Sky
Vintage: Yes
Brand: Unmarked
Type: Mask
Model: Face Mask
Theme: Abstract, Art
Production Style: Art Glass
Time Period Manufactured: 1960-1969
Country/Region of Manufacture: Mexico
Handmade: Yes