Hurrah! Nuummite, my gemsona is now complete! It has taken two full concept designs to get to this, and I freaking love it!!
I've used diamonds as Jasper and Peridot have diamonds in their designs and the two are Homeworld gems, like Nuummite is going to be. Her gem is on her tongue, so when she summons her battleaxe, it looks like she's pulling it out of her throat. I might redesign her gem slightly so it's on her tongue instead of being her tongue, IDK.

Her background is vary vague at the moment. For now, she's working on the Homeworld, communicating with Peridot and Jasper on their way to check on the cluster. After the ship got destroyed and they lost communication with Peridot and Jasper, Yellow Diamond closes the mission. Nuummite still attempts to communicate with Peridot afterwards, only to be caught by Yellow Diamond. After dealing with a strict punishment, she is threatened that if she attempts to communicate with them any longer, she will be shattered.

That's what I've got so far, but I'm working on it.