Geology Analogies

I tutor science for my school, and recently was able to add geology to my list of classes I tutor, which is amazing because now I get to be paid for talking about geology. So today I had my first client, and while explaining some concepts, I came up with two analogies. I thought they were pretty fun and useful, and the student lit up after I had finished as they had just grasped the subject; however, I was wondering if I could improve these analogies, or if I had overlooked anything. Please keep in mind, though, that this is an intro class aimed at non science majors

1. Bowen's reaction series:

I forgot where I found this, but if you know please tell me and I will add proper credit.

This mostly deals with the continuous reaction series; I was attempting to explain why the heavier elements form minerals at higher temperatures. To do this, I linked minerals in a melt to children on a playground, and the heat is analogous to massive amounts of sugar fed to them. As they run around the playground, the bigger kids will collapse first and the lightest most energetic kids will be the last to collapse, with collapsing being analogous to coming out of solution.

2. Crystal Formation in Phaneritic and Aphaneritic rocks
In this analogy there are two sets of kids with a lot of Lego blocks in two separate rooms.  The Lego blocks are analogous to the molecules in the melt, and the shapes they are built into are the crystal shapes of the minerals. The group in the first room isn't given much time and each kids quickly puts together very small geometric shapes.  This is analogous to Aphaneritic rocks cooling on the surface. In the other room, the kids are given a lot of time to build their shapes, and instead combine the shapes each kid makes into much larger shapes.  This is analogous to Phaneritic rocks.

So do these analogies make sense to you? Can they be improved? And if so, how?