Introduction
Ice is a mineral that affects us everyday. Yet many of us do not know that ice is actually a mineral. This frozen state of water actually has crystals and all the physical properties of a mineral.Ice has several important attributes and uses that helps make the living earth what it is today. The different types of ice such as glaciers, ice caps, and snowflakes have a definite affect on the climate of all the geographic regions around the world. Naturally, the more natural ice there is in a given region, the colder it will be.
With the current technology ice is also very important in climates that are relatively warm all year round or at least part of the year. For instance, on a hot summer day in Kansas after you have been working outside for a while, you might be compelled to go inside and pull a few ice cubes out of the freezer for a cold drink.
Yes, ice affects everyone on a daily basis. But what is ice exactly? The physical properties of ice are shown below.
Physical Properties
Ice has a white color but can appear blue or colorless. It is a part of the hexagonal crystal system with a crystal class of 6/m 2/m 2/m and a space group of P63/mmc. It can occur as a dihexagonal dipyramidal. Ice has a hardness of about 1.5, a specific gravity of 0.9 (just lower than water at 1.0), and a density of 0.99 grams per cubic centimeter (just lower than water at 1.0). The luster of ice is vitreous to dull. It has a white or no streak and no cleavage. It has a brittle or conchoidal fracture and it mostly has a massive habit. However, individual crystals have a dendritic habit with many complex tree-like "branchs."Although ice has definite physical properties, it is classified in many different types. Several of these types are illustrated below.
Types of Ice
Ice caps or ice sheets are the huge layers of ice that exist on or near the Earth's poles. They exist because of the below freezing temperatures almost all year round in these regions due to the sun's rays striking the Earth at very low angles and the high latitude.
East Antarctic Ice Sheet
Image taken from
http://www.glacier.rice.edu/land/5_iceofallshapes.html
Icebergs are large masses of ice that break off from ice caps or ice sheets. They float at the water surface because the density of ice is less than the density of water.
Images taken from http://www.glacier.rice.edu/land/5_iceofallshapes.html
Hailstones are small chunks of ice that form in the supercell of a thunderstorm. At the top of the supercell the temperature is below freezing. Moisture in the cloud freezes and starts to fall through the cloud. Updrafts from the storm circulate the hailstone through the cloud several times until it has gather enough mass to fall to the ground. Hailstones can be a dangerous hazard, especially if they get very large. They can do tremendous damage to property and have even been know to kill cattle!
A hailstone a bit larger than these broke this windshield.
Image taken from http://www.chaseday.com/hailstones.htm
When the temperature from a cloud all the way to the ground is below freezing, snowflakes or snow crystals may form as precipitation. Snowflakes and snow crystals are nearly the same thing. A snow crystal is a single ice crystal that forms in the atmosphere and makes its way to Earth. These individual crystals are very small. An ice crystal is a few millimeters in diameter or even microscopic in size.
Snowflakes are simply a group or collaboration of snow crystals. This is the dendritic form of ice. Snowflakes tend to look like they are branching out like trees. Snow can be very pretty but can also be a hazard if too much snow accumulates in one area over a short period of time.
Photograph of a snowflake using a photomicroscopy apparatus for high resolution.
Image taken from
http://www.its.caltech.edu/
~atomic/snowcrystals/photos/
photos.htm.
Snowstorm in Bethesda, Maryland.
Image taken from http://www.qsl.net/n3prz/990108.html
Freezing rain is moisture that freezes into ice crystals as it travels toward the ground. Sleet is moisture that starts from the cloud in liquid form, freezes into ice crystals for part of the way down, and starts to melt again before it hits the ground. These two phenomena are not considered hail because not all of the H2O molecules are frozen all the way to the ground and are not created in the cloud itself.
Ice and Weather
Weather determines the temperature, precipitation, and wind systems of a given location. To a certain extent it determines the lifestyles of people on a daily basis, such as clothes to wear and outside activities. In most climates, with weather comes ice. Ice is apparent in climates where the temperature drops below freezing for any amount of time during the year. Of course, to make ice you need some kind of precipitation, as well.Many times ice can be a weather hazard. In the types of ice mentioned above, there are a few hazards associated with ice and weather. Hailstones can cause large amount of property and financial damage as well as injure or even kill a human being. Snow can impair vision when driving. Too much snowfall can make some roads impassable until it melts. There is one hazard that has not been discussed yet. That is ice that glazes the ground and makes it very slick. This kind of ice can cause injury just by walking outside and slipping. It also causes a number of automobile accidents every time an ice storm happens.
Conclusions
Ice is a mineral that affects people everyday in one way or another. It is considered a mineral because it is a natural, inorganic, homogeneous solid with a definite chemical composition and crystalline structure.There are many different types of ice. Some are huge masses that cover the ground for many miles and others are small chunks that fall from the sky. Individual crystals form at below freezing temperatures and grow together.
Ice and weather are strongly related in most climates. The colder the climate and the more precipitation it has, the more ice will be prevalent. Snowstorms and hailstones can be a hazard and should be approached with caution.
References
Mineralogy Database, Ice, World Wide Web URL: http://webmineral.com/data/Ice.shtml. Retrieved on 19 November, 2002.http://www.chaseday.com/hailstones.htm
http://www.djburnette.com/projects/ice.html
http://www.glacier.rice.edu/land/5_iceofallshapes.html
http://www.its.caltech.edu/~atomic/snowcrystals/photos/photos.htm
http://www.qsl.net/n3prz/990108.html
Klien, C. S. and Hulburt, Jr., C. S. 1993. Manual of mineralogy. Revised 21st Ed. NY: John Wiley and Sons, Inc.
http://www.emporia.edu/earthsci/outreach/html.htm