The golem that Adelaide pointed to is indeed much different than the other golems. While the others have very visible ore colors on their bodies, like iron, copper, and gold, the golem she pointed out is much different, as it contains blue, white, green, red, and a few more colors unique to the rest of the golems.
But just because it has various colors doesn't mean the ore that they are looking for is present there. But because Elaina doesn't doubt her children, she swoops in to attack the golem.
Golems are structures that run with a core. To kill a golem, one needs to either wear it down the golem which is harder to do or kill it by destroying the core that causes it to move and function, as it acts as its brain and heart. Without it, they are going to crumble, and sometimes, they will turn to dust as the core is the only thing that is keeping that golem solid and walking.
