I've just been going through the old Ask the Dev posts, and found this:

Q. What steps can I take to ensure that the element of my synthesis does not become unstable?
A. The element has a chance of becoming unstable whenever any step of the synthesis process ends in failure. It is at its most susceptible when the glowing light representing the craft is colored, and is at its most stable when this light is white. Additionally, the chances of an element becoming unstable increase as a synthesis attempt nears completion. Naturally, the element which becomes unstable is determined by the type of crystal or shard being used.

However, earlier I was making Silver Chakrams using fire and wind shards, but it was the ice element and the lightning element that when caotic!

Could anyone help explain this to me pls

Thanks