So I have a bottle of 100% tung oil I recently purchased from Woodcraft. Right on the bottle it says you can place marbles in the bottle to displace the air and keep the oil from polymerizing. Stole some marbles from the wife's craft supplies and 3 weeks later they've dissolved Thought they were real glass. They break like real glass (took a hammer to one just now to see). Haven't a clue as to what they really are and more importantly if they will affect the tung oil. Thoughts?