Once you get into the Booster Respin Feature, there are six different ways it could go. This is because there are six different formats, all represented by different gemstones you can use.
The first is the Ruby Booster Respin, and it can award respins any time Ruby Symbols turn into Wild Symbols on stacked reels. Next up is the Topaz Booster Respin, which occurs whenever you land four Yellow Topaz Crystal Symbols on the reels. Once it gets going, it will reward you with a respin and morph all the Crystal Symbols into Boosted Symbols.
Following on from here is the Sapphire Booster Respin. This is activated any time four Blue Sapphire Crystal Symbols land on the reels, and Sapphire Symbols will be stacked on reel four to elevate the Blue Sapphire Symbol Wins.
Eventually, the Super Booster Respin Features start combining with each other. The first example of this is the Ruby and Topaz Super Booster Respin. This is where Ruby Symbols, Topaz Symbols, and Wild Symbols can stack and turn into Wilds. Any wins generated on these Wild Symbols will be multiplied by five. The Ruby and Sapphire Super Booster Respin plays out in a very similar fashion, as do the Topaz and Sapphire Super Booster Respin.