..This plane is lousy with critters that'll eat you as soon as look at you. Crysmals, xorn, khargra, end even a thoqqua or two lair here. Don't go to the Mineral plane without a good, sharp axe, I say"
Gaddin Hammerdome, dwarf miner
Checking these old Planescape manuals form the mid Nineties.. so many wonderful inspirations for concepts.
Here is a Gem Eater, a minute creature that inhabits the Quasiplane of Minerals. As the name says it only feeds of gems and crystals. They are territorial and tend to assume the colors of the most abundant crystal in the area. Males are not aggressive but females lay eggs in bigger creatures ears.
Adding some additional versions of the concept.. Sculpted in Zbrush (I really wanted to sculpt a winged creature), rendered in Octane, ZDepthed in Nuke, gave it the final touch in Photoshop. As I see it, the red variant lives in a zone rich of rubies, the purple of amethysts.
