Gem chests can drop ingots. I’m assuming it’s spread over all of the rarities.
VIP chests represent slighty-better gem chests as they restrict their pool to higher-rarity versions of what gem chests drop. For example, they only drop 2 Arcane or 2 Celestial traitstones, rather than “one of any rarity”.
Why don’t VIP chests also drop 1x higher-rarity ingots in the pool? I’d definitely spend more gems on VIP chests if one of the drop slots was a Legendary or Mythic ingot.