Zardnaar
Legend
I don't care much for FR lore, but I feel they should change some aspects of it over editions.
I think they're no longer considering anymore that Dwarves couldn't be Wizards before and no longer acknowledge any lore about why they couldn't and why that changed.
And I wouldn't consider Amethyst Dragons to be that obscure, they're just outside the core 10 Dragons. They're less obscure than Deep Dragons.
Deep dragons have been in several novels and have made it into miniature games.
Probably better known than amethyst dragons.