Living gems fight back against a terrible enemy that wants to smash them. No, it's not Steven Universe. Instead, we're on Land of the Lustrous, a series about living gems in a near empty world, hunted by Lunarians, who come from the moon to turn them in to jewellery.
There are 28 of them, all lead by their Sensei, but the weakest of them all is Phosphophyllite, who has no purpose in life, being very low on the Mohs scale of hardness and so is no use in a fight.
Which is why she spends her time trying to find things to do, and so ends up rather impressively stuck in the war between the Lunarians and the jellyfish creatures of the sea.
This is a bit of a strange one. The animation is CGI, and is generally fluid. It doesn't have that jagged appearance of something like RWBY, and works rather well for the various creatures. Having watched all of the series, the animation style is absolutely the best part of it, with the fight scenes being both exciting and dramatic.
It is a shame however that the visual design of the gems is not terribly interesting. They have more or less a single form, with the main difference between them being their varied hair colours.
It's funnier than you might expect, involving some impressively silly scenarios and interpersonal conflict that doesn't really fit into the overall conflict. Still, actually makes for some of its best bits. This often comes from Rutile, the doctor, who takes a rather proactive approach to maintenance of her hard yet brittle companions. But certain other characters do tend to have a fun dry wit.
There's potentially quite a good story in here, but it feels weirdly stretched thin. There are about half a dozen threads that could potentially be the main plot, but none of them ever get more than about two episodes worth of time, and some significantly less. It doesn't seem to be able to work out exactly what story it's intending to tell, which does not help its quality. Finds its feet about three quarters of the way through, but that's a bit too late to really save it.