@whostolethebatmobile ,
Early in this thread (or earlier) I gave some of my background which is solid state physics current working on materials science for batteries and previously semiconductors. I won’t bore you with my degrees.
This is the problem when charlatans and good intentioned reference things they lack the background to understand. Diamond is an insulator. Detonantion diamonds even with a carbon layer, or gold surface treatment (they are working on that to improve lateral flow tests -- think Covid rapid tests), are still poor conductors. The conductive layer is thin compared to the bulk. Most of the conductivity comes from surface area, though in plastics you have different mechanisms.
A more appropriate article to reference is this one:
Conductivity of detonation microdiamond under pressure
The initial electrical conductivities were 2.5 × 10−5 and 2.5 × 10−7 Ohm−1 cm−1 under atmospheric conditions and in vacuo, respectively,
Note that higher value is from absorbing water (hard to do in oil).
Other studies showed even larger variation
The G value changed from 10−12 to 10−5 Ohm−1·cm−1 at relative humidity range from 0% to 95%.
Since you are educating me on nanodiamonds and conductivity, perhaps you could relate these numbers to how they compare to copper?
Does it occur to people that there are people who understand these things in detail, certainly far better than some internet charlatan?