Bronze is said to be the metal of air, but at the same time silver has been given that position (see Sartar: Kingdom of Heroes, page 69), and Orlanth teaches magic to enchant the metal.
It seems plausible to conclude that silver is the metal of the Middle Air, the realm of planets, winds, and moons, explaining why cults such as Yelorna and Sedenya claim silver as theirs.
To return from this digression, where does this leave Bronze? As a mixture of sky and ground, it is still a metal sacred to the storm gods, but even more so than that, as one of the most common metals in Glorantha, it could be said to be the metal of the Middle World. Where things are made of everything.
But sky and ground were not the only coupling in the gods age, it would seem likely then, that other alloys, native or forged, would exist in Glorantha, and be sacred to many people. Here are my suggestions for a few of them:
Second only to bronze in abundance, this metal is formed where fiery gold and earthy copper have been mixed. The result is a bright metal, that although superficially resembling gold, is much lighter and stronger.
The largest brass deposits are in Peloria, where it far surpasses bronze in prevalence, both as an ore and when used for tools. The Dara Happans call the metal "Lodrilli Gold", claiming that it was formed when Yelm's brother plunged deep into the earthy Oria, tainting his pure golden nature. They regard the metal as fit only for commoners, who use it for both decoration and toolmaking.
Even outside of Peloria, the metal's connection to that land is implicit, with brass often going by the name of "Pelorian Bronze". The residents of Sun County import a large amount of the metal, due to their fondness for it for arms and armour.
The Esrolians call Brass "Mountain Copper", for mountains often mark where fire and earth have met, and import most of theirs from neighbouring Caladraland. Shunning its usage for martial purposes, they instead the metal towards musical purposes, with great brass gongs and horns being used in many celebrations.
Also known as "Stygian Bronze", this dark and heavy metal was prized by Arkat's dark empire. An alloy of lead and copper, the metal looks much like bronze, but is darker, and the metal quickly tarnishes, developing a purple patina, leading it to be called "Liver-stone" in some regions.
In the Kingdom of Night, the metal is said to be a mark of Esrola and Argan Argar's marriage. The coinage minted by Ezkankekko is said to have been this metal, although few remain after the God King Belintar slew the Only Old One, and ordered all likenesses of him, including on his coinage, destroyed.
The mercenaries of the Black Horse County are often seen outfitted in scale-armour made of this metal, which they claim is the only metal able to withstand the rigours of Hell. Certainly the value of this "Hell Metal" has been proven in the middle world, as their armour has resisted the arrows and spear-heads of their neighbouring Grazelanders, who regard this metal as an abomination and wound upon the world.
Often said to be the "Night Metal", this alloy of tin and lead is rarely found outside of Ralious, Kethaela, and the Kingdom of Ignorance, where it was sacred to gods like Argan Argar, Xentha, and Basko. The metal is typically a dull grey, although when the tin content is high, the metal acquires a bluish tint to the discerning eye. Like its parent metals, pewter is soft and easily worked, making it unsuited for warfare. It is a popular metal for the making of tableware, with plates and drinking vessels forming the majority of pewter goods. The Kralori call this metal the metal of ignorance, and have banned its usage within their Empire, claiming that it dulls the mind and soul, although this is likely to be due to its association with Chen Durel.
When Gold and Silver are alloyed together, they form the metal known as electrum, or "White Gold". Electrum is commonly used to stretch gold supplies, alloying it with the more abundant silver to form a metal that resembles gold, although it is somewhat paler than its parent.
The Lunar Empire has begun using electrum for their jewellery, leading the Dara Happans to nickname it "Lunar Gold", any attempt at using it for coinage has been firmly blocked by the Lokarnos Cult, who regard it as an abomination. Likewise in Fronela, the city of Southpoint has abandoned the metal, blaming its taint for the Fronelan Ban and emergence of the Kingdom of War. Despite this, the metal is still popular in the west, both for coinage, and tableware.
Just as bronze has become a common name for any metal alloyed with copper, amalgam is the term known by alchemists for alloys of aluminium with other metals. These alloys are rare in nature, for the ever changing nature of aluminium does not bond well with other metals. Most are instead created by alchemists in their rituals to enchant other metals, for amalgams can be quickly separated by those who know the right magic, to leave liquid quicksilver and the remaining metal solid and purified. For just as water purifies and cleans by carrying away impurities, so does quicksilver absorb cleanse and purify any metal it is alloyed with.