Coal

Coal was a type of black object that was used in braziers. The phrase "not the warmest coal in the brazier" described someone who is cold and distant. In 382 BBY, the thief Tey Sirrek used this phrase to describe the Jedi Knight Oliviah Zeveron.

Text and facts from the “Coal” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.