You say this is a "high fantasy" story. Most such stories are set in completely invented worlds with cultures based on medieval or Renaissance times. Many of them use completely invented names for their characters.
So what are your other characters like in terms of their names? Do they have names that are identical to those drawn from some European language and culture? Or are they invented names which one doesn't find commonly in real life? If they are the former, which particular culture and language are they related to? Without knowing more about your fantasy world, it's hard to know whether or not what one would suggest would really fit in with the names of your other characters.
You do say the characters are named after minerals and dyes. Do people have surnames (family names) in your culture? Are those mineral/dye names given names or family names? And can you give some specific examples?
Garnet and
Onyx are two gemstone names which have been regularly used for boys as well as girls in modern American culture, and could lead to short forms Gar and
Nyx or
Nic, which would be masculine sounding. But I don't know if those would really fit in with the world you are creasting.
This message was edited 5/2/2022, 9:13 AM