The Silver Hammer was the metallic asteroid that hit Eurona, triggering global cataclysm and ending the Antediluvian War. It is named for the main tool of an ancient Euronian forge-god and, fittingly, contributed to the sheer mineral wealth of the continent. Thousands of years after the Hammer's impact, its intact core would be unearthed, and a few short years after that the Steelskin symbiote would emerge from within it.
The asteroid was roughly ten kilometres long at its widest point, and did relatively little direct damage to the area it impacted. This was thanks to the concerted efforts of the force-elemental antedivulians present, who used their abilities to greatly mitigate the damage of an impact. This protective act nevertheless exhausted the creatures to the point where they were defenceless when those that would become the Builders and the Kinemancers moved in to claim their elemental blood for themselves.
Another consequence of dampening the impact spread the force imparted by the asteroid across the entire tectonic plate upon which Eurona sat, rather than simply embedding itself in the plate or piercing through. This caused the Euronian plate to sink nearly a kilometre, which had a knock-on effect of triggering colossal seismic destruction across Aios, subsequently also causing megatsunamis to rage across the ocean and surface, devastating - though not totally wiping out - ancient humanity that now found itself the dominant force on Aios.