Mae's Real Stories

Memories for Miriam, Alice, Theo, Delia, Tessa and anyone else who would like to be here

Wednesday, May 02, 2007


Useful Stones

Stones are everywhere, big and small. People use stones for all kinds of things, or they collect stones because they are pretty or interesting, or they make statues out of stone. Scientists who study stones are called geologists or chemists or materials scientists.

Carriage Stones: Before people rode in cars, they used to ride in carriages pulled by horses. A carriage was very high up off the ground. If you wanted to get down from a carriage you had to take a very big step, and if you were a lady this was especially hard, because in carriage days, ladies wore very long dresses that got in the way. A carriage stone was like a step that you could use to get out of your carriage. The carriage stone in the picture is not too far from our house. It still has a metal ring where the carriage driver could tie the horses to keep them from running away. No carriages have been there for a long time.

When I was a little girl, horses and carriages were long gone, but when we took a walk, we often saw a white carriage stone near the street, somewhat like the one in the picture. We called it a wishing stone, and sat on it to make a wish.

Millstones: Long ago people discovered that you could use a very hard rock to grind grain or crush other types of foods to make them easier to eat.

At first, people tried to find stones the right size and shape, and would put some grain on the stone and grind with the other stone. But people always try to improve what they find. After a long time of using the stones that they found, people began to make millstones: special round stones that were good for crushing and grinding hard food, especially for grinding grain into flour or for pressing olives to get olive oil.

In the picture is an ancient mill that has been rebuilt in a museum in Israel. You can see the basket where the raw grain would have been held and the stone trough for grinding. Some ancient mills were turned by a person. Some were turned by animals like donkeys or oxen. A water mill uses a rushing river or stream to turn a mill wheel, which makes the grinding stones turn and grind the grain. Now people don't usually use stone for grinding: they use steel blades, which make very fine flour.

Gemstones: Beautiful stones that sparkle and reflect light are called gemstones or precious stones.
A diamond is a very hard stone made of carbon atoms. It's called a crystal. In the picture is a very famous diamond called the Hope Diamond. It is very large and blue in color, which makes it very special.

We have seen the Hope Diamond and many, many other gemstones like rubies, emeralds, and sapphires in the Smithsonian Natural History Museum in Washington. We have walked through the large exhibit of precious stones. Do you remember the geodes and jewelry and other types of stones like quartz?

Lodestone: A long time ago, people noticed that metal would stick to certain types of stones. They named these stones lodestones. How does a lodestone work? Well, Grandpa studies the science of materials like this. He says that the force that makes these paper clips in the picture stick to the lodestone is called magnetism.

Magnetism is a force inside some rocks or some kinds of metal. All things like stones are made of extremely tiny atoms. The important thing about lodestones is that iron atoms are lined up inside in a special way. This makes paperclips -- also made of iron -- stick to it.

Here's a really interesting thing: rocks with iron inside them sometimes are hit by a lightning bolt. The lightning bolt lines up the atoms. That's what makes them into lodestones. Most of the magnets we have (like refrigerator magnets) are made of iron without any stone in it, but they work the same way: the atoms are lined up. The atoms inside a refrigerator magnet get lined up in a different way -- not by lightning.

Remember: atoms are so small that no one can see them except with a special microscope.

Skipping Stones: Here is a way to have fun with a stone. Throw it across still water in a special way so that it skips up several times and makes a whole lot of ripples.

It's not really easy to get a stone to skip across the water. Some people can do it really easily, and some never get the feeling of how to make the stone seem to jump up over and over. If you find that it's fun to skip stones across a pond, you can stand there for a long time, trying again and again, and counting how many times it skips up and makes a new circle of ripples. Different people pick different kinds of small, flat stones for skipping. Do you know anyone who is really good at skipping stones?

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