What are rocks?

The big question this week, to start off our geology unit, was this: what are rocks? I realized quickly that I did not, in fact, know the answer, despite having a number of graduate credits to my name in the subject area of geology. Oops.

So I cheated and looked it up on wikipedia. It turns out rocks are a bunch of minerals put together. Big help that is to second graders, who have probably not heard of minerals. Anyway, I have been doing an informal poll and have not as of yet found any adults who can really answer the question of what rocks are, except for my dad, who was a geologist in a former life. But he still thought it was a thought-provoking and complicated question, and noted that often the simplest questions are the hardest.

We talked about it a bunch this week in school and sorted objects we found outside into three groups.

We knew these things were not rocks:

They were an apple, a leaf, some moss, some soil (although this one may be debatable, and we did find pieces of rocks in the soil), a feather, some bark, and a seed pod.

We knew these things were rocks:

And we disagreed or weren't sure about these things:

They were a brick, a piece of painted ceramic, and some sand.

I don't think it really matters if my students can define what a rock is, or if we ever figure out whether these "not sure" items are rocks or not. Thinking about it and discussing it is what matters. We've been making lists of properties that all rocks have in common, and properties that only some rocks have, and next week we have lots of different and more interesting kinds of rocks to examine, sketch, compare, and sort.

I am so excited about doing geology that I woke up extra early Friday morning to go to school to look at all the rocks and minerals we had in the curriculum kit and get them ready for next week. We are going to be smashing them open next week. Whoever knew rocks were so cool? (My dad's been trying to convince me of this for all 32 years of my life, I think, and I've never believed him. The life of a dad with a skeptical daughter is very hard.)

I love that in second grade we are asking questions that most grown-ups can't answer, and that don't really have right or wrong or cut-and-dried answers. Those are my favorite kind of questions.