@KingisNitro I think trees would be a better analagy. Trees not only don't have gender in a binary sense (no male or female) but they can even in an obscure sense get themselves pregnant. Not that pregnant as a physical description applies, they just mix dna from any one of the sixteen engendered parts on their own body until they get a fruit, then try and toss the fruit into an environment full of natural resources where hopefully a new plant grows.
Kindergarten anyone? Perhaps say gems reproduce by fracturing their crystals, embedding them in ground that contains all the chemicals and components sufficient to grow more crystals, bombard with energy to help them grow and suddenly a hundred new amethysts.....
In that respect where do mamillian gender roles even remotely apply?
I hate to tell you this but it KINDA implied that Kindergarten is NOT how gems normally reproduce and is seen by the crystal gems as parasitic then actual birth i think there a different method there. but your tree analagy kinda still works though.