Many players are still wondering about the gold chest droprates of items so here is a small overview.
I can not guarantuee that the numbers are correct so please take it with a grain of salt and consider the time they were opened and the amount of chests that were opened.
- Black Pearls did not exist in 2016
- Elemental Embers only dropped in the first half of the 2016 events (probably somewhere in Sep-Oct 2016)
- In the first half of my 2016 opening period, dragon boosts were offered, they then got swapped for base boosts (probably somewhere between Oct and Nov 2016)
If you have additional sources or data about larger numbers of gold chest opens, feel free to post them here.