Board Thread:Suggestions forum/@comment-90.216.74.242-20160210130627/@comment-26172435-20160210133303

FYI: See this blogpost by Mevans, in which he explains why he has disabled diamond ore generation and suggests to add Adamant to replace it later.

Also Amber has been announced. And Amber can be considered a gem, as it has hardly any practical purpose, assuming medieval technology.

Any new ores or shiny bits may be added ... main motive to do so, should be some meaningful, lore-fitting, purpose. Just being shiny wouldn't be sufficient justification afaic.