Black ore

Black ore can be mined at level 40 Mining. The mining site is discovered during the Lair Infiltration quest. It can be smelted with three pieces of coal and be used to make Black equipment with 40+ Smithing. This would be able to be trimmed by smithing while holding molten gold, made by using a gold bar with a furnace and 10 coal, and selecting "trim". Trimming armor would reward the player with crafting experience. In addition to being minable, 10-25 noted black ore would be available as an uncommon drop from Black dragons and King Black Dragon.

Note that the trimmed armour is a different armour as the trimmed armour from treasure trails. This armour looks like a gilded armour, but much darker. The trimmed version gives better stats then normal black armour, but mithril armour is still better. You need a Defence level of 28 to equip it.