... yellow, amber, pink, purple lab use Ground glass joints of borosilicate 3.3 pyrex are used in laboratories ... For example, a , , and with ground glass joints may be rapidly fitted together to a reaction mixture. ... spaces of the glassware components, ground glass joints are hollow on the inside and open at ... the ends, except for stoppers.Glass ground joints of borosilicate 3.3 pyrex types:Conically tapered ...