A while back we renamed "Mithril" to "Mithral".
If we want to be more lore accurate, "Adamantine" refers to an alloy typically made with 5/8 adamant, 2/8 silver and 1/8 electrum (which is an alloy of silver and gold).
The correct term for the ore is "Adamant", and it would make sense not only to rename it, but to consider putting gold and silver components into any recipes using it. We already see this with a few items, but mainly Silver.
Electrum could also be added as an ingot option, seeing as we have alloys like brass and bronze.