Hades 2 can be a bit weird about its resources since you’re never guaranteed to see them in a single run. Because their appearance is somewhat random, multiple runs could leave you still unclear about where to find certain things. G Rock, an item needed to create the Argent Skull weapon is one such example.
To be clear, “G Rock” isn’t what the resource is actually called. It’s Glassrock. As of right now, when listed as an ingredient, some items get abbreviated. It’s just kind of strange that the most important qualifier in the name was what squished down so much.
In any case, Glassrock is a mineral, which means that, just like silver, you need the Crescent Pick to extract. You almost certainly have it by now.
You find Glassrock (G Rock) in the Fields of Mourning, which is the third area on the descent route. This means you will need to be able to handle Hecate, as well as Scylla and the Sirens.
The good news is that once you reach the Fields of Mourning, Glassrock is hardly a rare resource. The bad news is that the areas are, true to their name, largely wide open areas where it’s easy to overlook something. If you have done the Reagent Sensing incantation, that helps, as it will point you in the direction of any resources once you’ve cleared the area.
You’re probably familiar with resources by now, so Glassrock (G Rock) looks like sharp, black rocks. They have a shine to them which signifies that they’re harvestable, but because of their dull color, they can be easy to overlook.
Once you have Glassrock, the most obvious usage for it is to create the Argent Skull. However, afterward, you’ll also find that G Rock is important in creating some of the Aspects, such as the Aspect of Thanatos and the Aspect of Artemis. For now, it might be best to just stock up, which means taking the crescent pick with you to the Fields of Mourning.