Mini Me Geology Blog » geology for kids

How to Focus a Hand Lens / Hand Magnifier

tracyb — Thu, 24 Sep 2009 16:09:52 +0000

Hand lenses / hand magnifiers are very useful tools for studying small objects such as rocks, flowers, or bugs. Young children especially benefit from the use of a hand-held magnifier as they are often not able to use a microscope but can easily operate the hand magnifier. Your Mini Me Geology hand magnifier has two different strengths – 3X and 6X. The large area has a 3X magnification which means that the object you are looking at will appear to be three times its normal size. The smaller area has a 6X magnification which means that the object you are looking at will appear to be six times its normal size.

Here are the steps to follow to properly focus a hand magnifier.

Gather your hand magnifier and small objects.
Sit in an area with good lighting or sunlight.
Hold the object on the opposite side of the hand magnifier from your eye.
Looking through the larger, 3x, area of the hand magnifier.
Move the object or the hand magnifier until you can see clearly through the lens.

If you want to see certain part of the sample even more closely, use the smaller 6X area and focus the lens the same way described.

New Ask-a-Geologist Question: Layered Rock

tracyb — Sat, 27 Jun 2009 13:41:10 +0000

Question: What is the term for the layering of sedimentary rock?

Answer: Often these rocks are called layered or banded rock. Sometimes people use the term “banded” when referring to layered rocks with distinct color or mineral changes. This photo of a banded sandstone shows the distinct layers or bands of the rock. In this case, the red color in some sandstone bands was caused by iron being deposited within the rock. The layers of a rock indicate a change in the composition of the material that makes up the rock such as the iron content or a change from mostly sand to mostly clay.

To see more unique rocks, visit www.MiniMeGeology.com.

EARTHQUAKES

tracyb — Thu, 25 Jun 2009 11:46:38 +0000

Earthquakes usually occur when the Earth’s crust moves along a fault, a break in the Earth’s crust, causing the location of the land to shift. There are basically three types of faults: normal, reverse and tear. Normal faults occur where the rocks pull apart and the rocks on the upper side of the fault slide downward. Reverse faults occur where the rocks are pushed together and the rocks on the upper side of the fault slide upwards. Tear faults move sideways instead of up and down, just as if the rocks were being torn apart.

This photo shows a fault line. If you follow the two gray layers with the white layer in between from left to right you will see the fault line.

The magnitude of an earthquake is sometimes measured on the Richter Scale (some scientists use other scales as well). The Richter Scale measures earthquakes on a scale of less than 1 (minor) to 10 (epic) and above. Earthquake with a magnitude less than 3 are not typically noticed by people but can happen up to 1,000 times each day. Earthquakes that have a magnitude of 7 or more typically cause the ground to shake noticeably and can cause damage to buildings and the land surface. There are usually less than 20 earthquakes each year that measure 7.0. Earthquakes greater than 7.0 are very rare and, in fact, a magnitude of 10 or higher has never been recorded. For more information on the Richter Scale and other scales used to measure earthquakes click here.

Earthquakes can occur both on land and under water. If the earthquake occurs under the ocean, a huge tidal wave, called a tsunami, can occur. Tsunamis are very dangerous and can flood a large area very quickly.

Here are some of our latest “Ask-a-Geologist” questions & answers

tracyb — Wed, 16 Jul 2008 06:27:39 +0000

Q: What is in magma that makes up a rock?

A: Magma is the term used for liquid rock which forms deep below the Earth’s surface. Magma can be composed of many different things such as silicates, alkalis, iron and magnesium. The composition of the magma will determine the type of rocks which it will eventually form.

Q: What rocks are changed by high pressure and high temperature?

A: The change of a rock by high temperature and pressure is called metamorphism. This is the process by which metamorphic rocks are formed. Any rock can be changed by metamorphic processes.

Q: What term for metamorphic rock with banded texture?

A: You may be referring to “foliation” which is the layering within a metamorphic rock. Foliation occurs when there is a strong pressure applied to the rock in one direction, just like when you put your hands flat together and push. When this pressure is applied, certain minerals, like mica and chlorite, grow with their long direction perpendicular to the pressure. This make the rock appear with layering and/or banding.

Every heard of a Herkimer Diamond?

tracyb — Mon, 23 Jun 2008 13:58:14 +0000

OK, today I thought I would talk a little about Herkimer Diamonds. If you know what they are, you’ll probably agree with me that they are so cool!

Sorry! Herkimer Diamonds are not real diamonds. Herkimer Diamonds are actually quartz crystals that are naturally formed with points on both ends of the crystal. These crystals are somewhat rare because in order to form with these double points, the quartz must have very little contact with the surrounding rock while the crystal is being formed. The term Herkimer Diamond can only truly be used with samples found in Herkimer County, New York, although double point quartz crystals have been found in other locations throughout the world.

You can see a photo of some Herkimer Diamonds here.

For more great information on Geology, Rocks and Minerals check out the Mini Me Geology website and our Dig into Geology section for more great information, free project and experiment ideas and puzzles!

The Rock Cycle – Dig Into Geology

tracyb — Fri, 20 Jun 2008 03:23:13 +0000

One of the most interesting topics in geology is the Rock Cycle. The Rock Cycle is the method by which minerals are made into sedimentary and igneous rocks, which are then made into metamorphic rocks. The cycle continues when all of these sedimentary, igneous and metamorphic rocks break down into mineral and small rock pieces and form new rocks. Are you still wondering what I’m talking about? Here is an example: The mineral quartz makes up common beach sand. That beach sand will, over time, form into a sandstone sedimentary rock. When a sandstone is buried and heated it becomes a quartzite metamorphic rock. The sandstone and quartzite can either be buried, melted and formed into part of a new igneous rock, like granite, or it can breakdown and form a new sedimentary rock such as conglomerate.

For more great information rocks, minerals and geology, visit the Dig into Geology section of our website.