Talk:Gems/@comment-24305970-20140513170735/@comment-24457062-20140514143343

It depends on your buildings and your strategy. On my first island I have all the fast XP buildings (European, icecream shop, cottages etc:) and they all have XP gems in them (sapphires, ice sapphires) given I play frequently. If you play slower, you might want to craft sapphires into amethysts and place them in buildings that earn relatively high XP/hr over a longer time period than Europeans etc: