Ruby

Ruby is a homeworld gem from era 1 who went through a lot. Her gem got cracked when trying to fend off the rebellion.. it was her own clumsiness that caused it, really. Though, homeworld, not having the proper tools to fix her gem fully, only managed to reduce the damage to a scratch. 

She isn't anything less of a fighter though! She uses her big arm for giving big powerful swings, punches and can now reach stuff a lot easier! 

Much like other gems, she got corrupted by the diamond's light and later uncorrupted and her gem fixed. She still prefers to have a big arm though.

Ruby is extremely clumbsy and makes stupid decisions without much of a second thought, she has her gem in the right place though. She is also rather stubborn and believes that if someone is good at their task, she would do phenomenal with it.