How old is our meteorite?
The meteorite fell to earth from interplanetary space. That is, it probably originated inside our solar system. Because it is an iron-nickel meteorite it probably was part once of a larger body, a planet or other large object that was broken up in a collision with another large object. Most of these collisions would have taken place in the first one or two billion years of our solar system which is about four and a half billion years old. That would make our meteorite probably about three billion years old, give or take a billion. That is really, really, really old, give or take a really.
How heavy are the rocks?
We have a big piece of petrified wood that doesn't travel on the van because it weighs about sixty pounds. Most of our rocks are a pound or two, the geodes and crystals weigh only fractions of a pound. We have tried to collect rocks that are big enough to be interesting to look at or are interesting enough that it doesn't matter if they are small.
How old is the pumice rock?
How old is the obsidian?
Both of these rocks were produced by explosions of the Valles Caldera volcano in the mountains behind Los Alamos and White Rock. I don't know if they were produced at the same time or during the same cycle of eruptions, but the last eruption was between one and two million years ago so that is as young as they can possibly be.
What is our newest rock?
Our newest rock is the concrete core sample which was cut out of a sidewalk sometime in the last twenty years. Concrete is a man-made rock, and I think this core was from a sidewalk somewhere up "on the hill" so it can't be more than fifty years old. There weren't sidewalks here more than about fifty years ago. Sometimes cores are cut to see what condition the concrete is in below the visible surface, other times they are cut to make a place to put up a new sign in the sidewalk.
The other young rocks are also man-made. Slag from the San Pedro Mine near Golden, NM is left over from a gold mining operation in the early part of the twentieth century, and we have one small piece of Trinitite in a plastic globe. The trinitite actually has a birthday, as it was formed when the sand below the first atomic explosion melted on July 6th, 1945.
How old is our oldest rock?
After the meteorite, which I discussed above, our oldest rock is a piece of quartzite from the Brazos Cliffs area near Tierra Amarilla, NM. The rock that forms these cliffs is the oldest surface rock in the state, and is about 1.7 billion years old. That is way before dinosaurs, in fact, it is possible a dinosaur may have tripped on our rock or turned it over looking for goodies to eat!
How many rocks do we have at the museum?
Please don't make me count them! In our rock museum, I think we probably use about forty rocks. We probably have three times that many either stored or in the sample bags. When we think of a rock that we would like to have for the program, we often go outdoors and look for it. It helps to know where to look.
How many pieces of pumice do we have?
We only travel with one piece of pumice, but you have to admit it is a good one! We have some small pieces, but pumice is so soft that when we take them around, they crunch against other rocks that are harder and they get ground into powder. So we usually leave them home.
What are our favorite and least favorite rocks?
I can only speak for myself, but all of the rocks in our program are favorites. My own personal least favorite rock is a boulder in a canyon near Taos that rolled one day when I stepped on it and I broke my leg.
My very best favorites are probably the meteorite and the dinosaur stomach rocks, but I am proud of collecting a very heavy piece of fossil pond scum that rarely visits classrooms because it is so heavy. Each of the rocks in the program has an interesting story, and most rocks you see around have good stories too. Sometimes it is hard to choose one rock story over another.
These are great questions, and as a teacher I can tell you that good questions are one of the nicest things you can give a teacher. Thanks for asking, and keep being good scientists!
