You need jewels for royal and ornate beams, which will be needed later, also all the faerie story uses jewels, and the jeweller trade is a good one if you have extra jewels for adamant which is very rare and you do need for Blythe sapling, and upgrading the deep mine which is needed as part of the core story,but never mind, the thing with the vital glow is you need mushrooms and lots of them and living wood, everything gives you seeds, magic garden, Ivy's hut, faerie respite, adventures, you will always be maxed on seeds, even during sister sister when you need lots of seeds I was always maxing out. When you have millions of coins you just keep building things, I also have six libraries, six markets, six taverns, six amphitheatres, six cathedrals, all level five and most stored, it gives you something to do.