 Glass and steel dildos have similar features.In most cases, glass toys are solid, and made of Pyrex or other types borosilicate glass (Schott-Duranglas and Simax), although their construction can vary depending on the manufacturer.Like steel, glass toys may be used to apply firmer pressure than silicone can to a female's G-spot (urethral sponge) or a male's prostate gland.