Oh and last tip that might be useful for those with plenty crystals and gold.
If converting and salvaging crystals, make sure to convert or salvage the exact amount of crystals needed to complete the achievement to complete it more than once because if not, if you just salvage 1000 crystals, it only completes that crystal feat once as it can’t calculate if the achievement has been done more than once.
For example, if you got 374/375 crystals used to get ultra rare crystals, if you salvage 1000 crystals, it will only complete the feat once which is annoying for sure. However, if you just salvage one crystal or convert when 374/375, it completes the feat. Then if you salvage or convert exactly 375 crystals, it completes the feat again. This at least can get you a few more ultra rare crystals if you want to salvage a lot or convert or build a lot.