Dwarven Rocksteel

Grunting and puffing from exertion, the small group of Dwarves kept their heavy hammers low to the ground. The volcanic black of the metal seemed to heat up with each Dwarven breath as they waited for their moment to strike. The Duergar bandits outnumbered them, their crossbows at the ready. The chief bandit approached and asked for their surrender. The lead Dwarf raised his hammer and in a steady motion crushed the skull of the Duergar. Heavy fire of crossbow bolts rained down on the armoured Dwarves and when the weapons were emptied the Dwarves were unscathed, broken bolts at their feet.
There are many kinds of ore, metals, and forged items throughout all of Aerith. Many races are adept at forging and creating weapons and armour of exceptional quality. Dwarves, Goliaths, and Humans make excellent heavy weapons and armour, items of solid use that help protect their races, and make life easier. Elves and Gnomes make lighter, more intricate, and specialized items that combine beauty with functionality.
Three types of specialized metals can be found on Starhelm; Airsteel, Rocksteel, and Moonsteel. The items they create are unique and wondrous. The sturdy and formidable Dwarven Rocksteel is detailed below.
Rocksteel is a rare metal forged by Dwarves. Like the people that craft with it, it is heavy, solid, and durable, making it ideal for dealing great damage or protecting against mighty blows. Unfortunately, it is also difficult to wield with much precision. It is the hope that one hit will be sufficient to end the battle.
As with Airsteel, the qualities and benefits vary depending on the amount of Rocksteel that is present in the creation. Since Rocksteel is more rare and the Dwarves value it highly, there are very few items made entirely of Rocksteel. Still rare, but less so are the items that have amalgams of Rocksteel and other metals that still allow some benefit of the Dwarven ore. The colour of Rocksteel can vary but it is most often a dark grey colour.
The process to create Rocksteel involves magically enchanting Adamantine in its liquid form. This ancient enchantment was discovered by the Dwarves back in the times of Haven. More Dwarves know the process for creating Rocksteel, than the Elves know of Airsteel, but it is still rare to find. The process and enchantment to create it is so complex and requires such rare components, many Dwarves do not often craft it on a regular basis.
Similar to Mithril, the rarity of Adamantine forces many Dwarven forgers to mix it with another metal. Iron is most often used but platinum is preferred for its density and ease of enchantment.
The process of making Rocksteel is still unknown to all but the Dwarves, and a very select few others, but the cost and skill needed makes it very rare.
The qualities and benefits of Rocksteel vary depending on the level of Rocksteel present in the making of the item.
Rocksteel weapon are strong and durable. All Rocksteel weapons deal double damage against objects, and can bypass resistance and immunities to slashing, bludgeoning, and piercing damage.
Rocksteel armour is heavy and resilient, turning a critical hit against you into a normal hit. You gain advantage on ability checks and saving throws against being knocked prone, as well as on Athletic checks to avoid being grappled.
Rocksteel shields reduce the damage taken from slashing, bludgeoning, and piercing damage.