I was studying for heat transfer and I fell in the rabbithole of the physical properties of diamonds.
One might think that Bortz is simply supposed to be bort, the impure, rough diamonds that are considered too dirty and ugly to be used in the jewelry industry. The glove kinda fits; mono-crystalline diamond is beautiful, but too brittle to be of any use, while bort is usually crushed and used in heavy industry, such as the machining of hard materials. In other words, bort is tremendously useful, where pure diamonds are just pretty.
However, Bortz is not in fact made out of bort. Bortz is actually made Carbonado, a rare kind of black diamond. Carbonado is a polycrystalline form of diamond, down to the nanoscale, unlike bort, where crystals vary widely in size. This is what allows Carbonado to have the greatest toughness of any diamond.
Carbonado is also truly black, occasionally shiny and kinda beautiful just like Bortz where bort is most often brown and kinda ugly, for a diamond.
Here's the most interesting part though. Unlike normal diamond, the mechanisms behind the creation of Carbonado are kind of a scientific mystery to this day. Carbonado diamonds have been dated to having formed around 3.8 billion years ago, much older than any common species of diamonds. Also, black diamonds are only found in specific spots in Brazil and the Central African Republic, right around where Africa and Brazil would have been joined when all continents were joined in a Pangaea, eons ago.
See where this is going? Some theories assert that Carbonado cannot form naturally on Earth and was brought here by a meteoric impact. This theory is further supported by the fact the porous structure of Carbonado could not form in the high-pressure environment of the Earth's mantle, and could only occur if it formed in a vacuum somehow.
So, to get to my point: We'll get Bortz's origin story and he'll have come from GODDAMN space, mark my words, screenshot this.