Could you use 3mm Steve H Terp pearls or any borosilicate terp pearl as rubies for the baller cover? Home › Frequently Asked Questions (FAQ) › Information › Could you use 3mm Steve H Terp pearls or any boros.... Posted by Steve K on June 6, 2023 No, only rubies and sapphires can be used for the Baller Series heater. Borosilicate will melt to the heater and damage it.