Just to clarify what was said about hardnesses by
@VapePerson in a single post, because I was thinking about this just the other day so I've enjoyed geeking out on it and want to share.
> Stainless steel is a 5 on hardness. It can't scratch quartz and once it's in place it's not an issue. The issue is that the balls will be constantly moving and, if they're harder than their container, will put microscratches into the harder surface and that you will be breathing in dust repeatedly.
We know the
mohs scale of mineral hardness values for the 3 pieces
The ceramic cylinder is
somewhere in a 5, 6, or 7 range, made of alumina ceramica and is as hard as sapphire meaning the rest of this isn't as applicable, but I'm leaving it otherwise.
The quartz is a 7 (see the first scale), and the glass heater cover is made of
scientific glass ("Glass Style: Scientific"), so it's between a
6 and 7.5 on the hardness scale.
Assuming that everything is ideal (7/7/7 scale ratings of all three) we will never see any scratches on anything. Minimal scratching of the heater cover and balls could occur if balls aren't packed tightly enough and whirr around the cylinder.
Once we start introducing things like rubies and other materials that have tougher hardness, then any of the materials in there could get scratched. This is especially true if the balls are whirring around because they're light enough to be lifted into the air from a draw. It's not just about heat retention but that mohs hardness of the materials in use.
By choosing quartz over glass, you're introducing the ability for a stronger heat soak but also potentially getting micro-scratches which turn to dust, again - if the balls are whirring. Like
@ohmygodimsohigh said though, they ideally should not be as you want as much thermal soak as you can get , that is until more balls means the ones at the top are stealing heat from your air, not adding to it.
Hope this helps someone! And please correct me if I'm incorrect on anything. I'd rather learn than spread false info unknowingly.