Mineral spotlight: Ice

It is about that time in the winter season when the warmth of the holidays has worn off, and those of us in Michigan are left with the cold and snow for a couple more months. Roads and walkways remain slippery, and the air is unforgiving to skin.

Ice, as abundant and inconsequential as it appears, is in fact a mineral. The classical definition of a mineral contains five criteria: a mineral must be solid, inorganic, naturally-occurring, have a set chemical composition and a definite crystal structure.  Ice fulfills all of these requirements and is on the International Mineralogical Association official list of minerals, along with over 5,000 others.  

Ice is a solid, it is not organic, it has a hexagonal crystal structure and it is an oxide mineral with the chemical formula H2O.

Ice has many physical characteristics which make it a highly unique mineral. Ice has a hardness of 1.5, meaning it can be scratched by your fingernail. Ice has a specific gravity of 0.9, which is why it floats when placed in water, which has a specific gravity of 1.0.

Ice can form in many different habitats. Icicles, for example, are a stalactitic form of ice, and the intricate hexagonal crystal form is easy to see when you examine snowflakes closely. The abundance of ice at Earth’s surface, the hydrogen bonding in its crystal structure, the very low density and low melting point (0 degrees Celsius) make ice an undeniably unusual mineral.

You won’t be able to find any examples of ice in the Calvin College collection, but you can see fine examples outside this February on your way to visit the Dice Mineralogical Museum on the first floor of North Hall, open this semester from 12:30-4:00 pm on Wednesdays, Thursdays and Fridays.