The ground here is hard-packed, but not nearly packed enough to be a match for Bella's sword. Punching it through the ground breaks it up enough that it's easy to pry out chunks with the sword. She might have to get her hands a little dirty too, but there's a creek right there.
Soon enough, one of the chunks of dirt pried up shows a chunk of something harder. Extracting it from the dirt and bathing it in the creek reveals a guildplate-shaped object of reddish-silvery-golden metal. It's not exactly the same shape as Bella's own guildplate; it's comparatively slightly thinner, slightly narrower, and the vertices and edges slightly rounded. But if your prior probability was that this was a modern guildplate put through some magical catastrophe that wore off all the writing, you could easily see this as being what remained of a guildplate the same shape as Bella's after it was exposed to some horrific orichalcum-destroying blast.