I consider it necessary to make emeralds and sapphires more useful because they are literally the most useless minerals (even the descriptions of objects indicate this: sapphire has old information about crafting mana potions, and emerald generally has an empty “crafting material”), one is used only for crafting soulcatcher, the other for paint and ice dragon (blocks doesn’t count)
Emeralds can be used for some crafting, for example, to change the crafting of the staff of life, in which emeralds and kryptonite will be mixed
However, I have no particular ideas about sapphire, it is used in optics in real life, but I do not know how to tie it up in the game. Maybe you will have more interesting ideas.