Ear Gauges. Hand crafted Pyrex and Soda Lime glass plugs and ear tunnels. Flame sculpted and hand carved plugs by Gorilla Glass and Glasswear Studios. Pyrex (Borosilicate glass) has a high resistance to thermal shock and requires intense heat when formed into shapes. When it cools it has a tough, scratch resistant surface which makes Pyrex jewelry some of the most durable glass jewelry available. Gorilla Glass pioneered the use of Soda Lime glass in body jewelry. Soda Lime glass is widely used in food and beverage containers and art glass. It contains Silica, Soda and Lime in varying proportions.