@RustyOldNail
Quartz is another material I couldn't find a good source for. I started with some jewelry quartz that just melted when I torched it and then I couldn't find anything after that I trusted. There was a couple reports of Quartz melting in SSV mods but they must have not been using good quality quartz or that would never happen.
Ruby has a higher specific heat though from what I can find (750 J/kg.K vs 510-650 J/kg.K from azom.com). They don't mention the sintering method which may account for range. Ruby would take longer to heat up but should hold more heat.
@invertedisdead knows his stones and could confirm if I'm on the right (or wrong) track.
Silicon Carbide is probably the most ambiguous commonly used vaporizer material.
There are so many grades and variants, with dramatically different thermal properties, that it would be nearly impossible to know which one someone was using without a proper COA / materials test.
In fact SiC ranges from porous foams with extremely low insulatory conductivity, up to diamond impregnated versions which rival single crystal semiconductor grade components.
All these properties, from the conductivity, to the heat capacity, to the density, to the porosity, etcetera; all play some role, it just depends on the goal and design of the device.
One extremely common misconception I read every single day is that changing one of these variables will allow for lower temp vaporization - that’s not true. Lower temperatures on the PID controller are due to a more efficient heating system, the boiling point of the compounds isn’t changing. An analogy would be thinking water boils at a lower temperature in a copper kettle than a glass boiling flask - it doesn’t. And Human lungs can’t even suck the air out of a sous vide bag, so they definitely aren’t pulling a lab grade vacuum, even though many university accredited “physics experts” will claim this.
Also we can assume that 99.9% of these balls are from China/Alibaba/DHgate, regardless of material. It would otherwise cost around a thousand dollars to outfit a ball vape, the reality is the ball trend sort of relies on these low prices. Once you take that away it’s not that viable of a platform; economically speaking as the beads can easily hit $5 a piece!