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.
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.
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.
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.
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?August 2006 September 2006 October 2006 November 2006 December 2006 January 2007 February 2007 March 2007 April 2007 May 2007 June 2007 July 2007 August 2007 September 2007 October 2007 November 2007 December 2007 January 2008 February 2008 March 2008 April 2008 May 2008 June 2008 July 2008 August 2008 September 2008 October 2008 November 2008 December 2008 January 2009 February 2009 March 2009 April 2009 May 2009 June 2009 July 2009 August 2009 September 2009 October 2009 November 2009 December 2009 January 2010 February 2010 March 2010 April 2010 May 2010 June 2010 September 2010 October 2010 November 2010 February 2011 May 2011 September 2011 March 2012 April 2012 May 2012
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