A new way of looking at ice

This morning, Mid-Michigan woke up to find everything covered in a layer of ice.  The icy road meant that dozens of schools throughout the state canceled classes for the day.  Weather conditions haven't changed so there is a good chance that classes will be canceled again tomorrow.It's winter here in Mid-Michigan.  During winter you might expect to see everything covered in ice and snow, but have you ever thought about what ice and snow are?

The obvious answer is that ice (and snow) is the solid state of water.

The less obvious answer is that ice is a mineral.  

Yes, a mineral.

Like the thing that rocks are made of.

How is that possible?  If you look at the definition of a mineral, ice checks all of the boxes.  A mineral is a naturally-occurring inorganic crystalline solid with a specific chemical composition.

Ice is naturally-occurring.  Ice can form outdoors when the temperature drops below 32 degrees Fahrenheit.  (As I write, the temperature outdoors is 28 degrees.)  Ice that forms in your freezer is not a mineral because it would be considered man-made.

Ice is inorganic.  Inorganic simply means that it has never been alive.  Things might live in ice, but the ice itself has never been alive.

Ice is crystalline.  Ice forms crystals that have a specific internal structure - the water molecules that form ice bond together in a predictable pattern.  Liquid water and water vapor form much looser bonds and do not lock together in a predictable patter.

Ice is a solid.  When water drops below 32 degrees Fahrenheit, the molecules of water bond together to form a solid.  Only in its solid form can water be considered a mineral; neither liquid water or water vapor meet the definition of being a mineral.

Ice has a specific chemical composition.  Ice is formed from bonded molecules of water, each composed of two atoms of hydrogen and one atom of oxygen.  Other elements or molecules may be included in the ice, but the ice itself is formed only from the water molecules.

Ice is the only state of water that can be called a mineral.  If the ice melts or evaporates to form water vapor (a process known as sublimation) it ceases to be a mineral.  Due to the ability of water to shift states of matter, ice is a very ephemeral mineral across most of the earth.  In mid-latitudes such as where Michigan is located, ice can only be found during roughly half of the year.  At latitudes closer to the equator, ice would only be found in the highest elevations where the temperature can drop below the freezing point.  It is only in the highest elevations and the highest latitudes (the Arctic and Antarctic) that ice can be found year round. 

It's fun to look at familiar things in new and unexpected ways - like looking at ice as a mineral.  Right now large portions of the United States and Canada are rich in naturally formed ice, but come the period May to September it will be unavailable at any price throughout much of the same region. 

A teaching highlight

Testing the properties of pyrite and quartz

Last Friday while teaching about the different properties of rocks and mineral, I had a 3rd grade student exclaim "I feel like I'm in college!"

I told him that I learned the same stuff when I was in college.

His response, "Cool!"

It totally made my day

Nature Geek Vacation Destinations - A.E. Seaman Mineral Museum (Houghton, MI)

One of my favorite destinations in the state of Michigan is the A.E. Seaman Mineral Museum at Michigan Technological University.  Michigan Tech and the Seaman Mineral Museum are located in the city of Houghton, MI.  Located on the Keweenaw Peninsula in Michigan's Upper Peninsula, Houghton is approximately a seven hour drive from Mid-Michigan. 

The Seaman Mineral Museum is named after Arthur Edward Seaman, the museum's first curator.  Seaman was the head of the Department of Geology and Mineralogy at the Michigan College of Mines (now known as Michigan Technological University) and became curator of the museum upon retiring from teaching.  His personal mineral collection was donated to the museum upon his death.

The Seaman Mineral Museum is the official mineral museum of the State of Michigan and contains the finest collection of Michigan minerals in the world.  A large portion of the museum is dedicated to copper and iron ores that can be found in the western Upper Peninsula.  During the late 1800s and early 1900s, Michigan was the copper capital of the world with an estimated 11 billion pounds of copper being mined.  Much of this history is preserved as part of the Keweenaw National Historical Park.

Two boulders, both alike in dignity...

Last month I wrote several posts about geologic concepts (cross-bedding, original horizontality, and superposition).  Every photo that I shared in those three posts was of sedimentary rocks (sandstones and shales).  This focus on sedimentary rocks was not intentional - I did not intend to ignore the fans of igneous rocks and metamorphic rocks.  In order to make up for this oversight, and to restore peace in the geologic community, I would like to share an image of a igneous rock and one of a metamorphic rock.  Both of these photos were taken over this past summer during my vacation to Maine.

The first rock is a granite boulder with a very coarse texture.  The size of the crystals in this boulder indicate that the magma that formed this rock cooled very slowly, deep below the surface of the earth, allowing large crystals to form.  Three minerals can be easily seen in this boulder:  black crystals of Biotite Mica, smoky gray Quartz, and large tan Feldspar crystals.

A coarse granite boulder

The second rock is a boulder with metamorphic origins.  Metamorphic rocks are rocks that have been changed from one rock type to another by intense heat and pressure (or through chemical interactions).  This boulder is composed of a type of rock known as Ellsworth Schist.  The dark grayish-green rock is called Chlorite.  The pale layers between the the Chlorite are bands of Quartz or Feldspar.  The layering within the rock is called foliation.  Foliations form when the the pressures that cause the rock to metamorphose are unevenly applied.  The folding within the foliations show that this rock was subjected to further pressures perpendicular to the plane of the foliations.

Details of a Ellsworth Schist boulder