1. Moh’s Hardness Scale By Becky Clark

2. Some minerals are softer than others. How hard a mineral is can help identify it. We measure the hardness of minerals by scratching them. In 1822, Frederick Mohs published his scale for determining a minerals hardness. On Mohs scale, each mineral can scratch the ones below it. Talc, for example, is softest, with a rating of 1. A diamond is hardest, with a rating of 10.

3. How to Perform the Test 1) Select a fresh, clean surface on the mineral to be tested. 2) Hold the mineral firmly and attempt to scratch it. 3) Look for a scratch or line.

4. "Tools" for Testing Hardness There are several simple "tools" people often have with them that can be useful in determining the hardness of an unknown mineral. Your fingernail has a hardness of 2.5. A penny has a hardness of 3.0 The steel paper clip has a hardness of about 5.5.

5. Mineral Scratched by Finger Nail? Scratched by Penny? Scratched by Paper Clip? Number of tools that Scratched?

6. The following table shows the hardness of these materials: 1 Piece of chalk 3.5 Penny 2 Plaster of Paris 4 Iron Nail 2.5 Fingernail 5.5 Window Glass 3 Gold 6.5 Steel File

7. SONG: MR. MOHS TOES