Mineral Hardness: Mohs Hardness Scale & Scratch Tests

Use the Mohs Hardness Scale to answer the questions. What is the hardness of a diamond? 10 5 2 9 What is the hardness of talc? 10 5 9 1 Which is the harder mineral: quartz or apatite? quartz apatite Anita is examining two minerals. She is holding topaz and fluorite. The topaz scratches the fluorite. Which is the softer mineral? topaz flourite Mineral Riddle:I can scratch topaz, but can NOT scratch a diamond. What mineral am I? corundum feldspar calcite diamond Mineral Riddle:I can scratch talc. Every other mineral except talc can scratch me. What mineral am I? gypsum apatite feldspar diamond Click on the blank and pick the correct word in each sentence. Use the paragraphs at the top of the page to answer. The hardness of a mineral is a measure of how easily that mineral can be scratched. You can test this property by using different objects, such as a fingernail, a penny, or a steel nail to scratch the mineral.Another way to test hardness is to compare a mineral to the minerals listed on the Mohs scale of hardness. Talc is the softest and is listed with a hardness of 1. A diamond is number 10 and is the hardest mineral. What is the hardness range of a mineral that can be scratched by a steel nail but can scratch glass? 5.6-6.4 3.3-5.4 2.6-3.1 9.1-9.9 What could be the possible hardness of a mineral that can be scratched by a copper penny but at same mineral can scratch your fingernail? 10 6.4 3.1 1.5 What could be the possible hardness of a mineral that can scratch glass, but not a diamond? 2.4 3.2 4.5 7.6 Calcite can scratch feldspar quartz apatite gypsum Apatite can scratch calcite quartz topaz corundum Topaz can scratch diamond corundum quartz Fluorite can scratch apatite corundum quartz talc, gypsum, and calcite A steel nail can scratch anything above 6.5 feldspar and diamond quartz and talc fluorite and apatite Demonstrating Mineral Hardness using scratch tests You are encouraged to replay a portion of the video in order to answer the questions below. 1. Describe what could you do to prove the softness of Talc (hardness of 1) and Gypsum (hardness of 2) (Selenite)? 2. Describe what you would do to prove Calcite (hardness of 3) is harder than the first two minerals tested? 3. What is harder, your fingernail or a penny? fingernail penny 4. Describe how you could prove Fluorite (hardness of 4) to be harder than a penny? 5. What do you notice about the type of scratch made on the glass by Quartz (hardness of 7) compared to Feldspar (hardness of 6)? 6. What does the ability of scratching the glass tell us about the hardness of the minerals quartz and feldspar? 7. Is Corundum (hardness of 9) harder than Topaz and Beryl? yes no 8. What is your proof that Corundum (hardness of 9) is harder or softer than Topaz and Beryl? 9. What mineral, not in the hardness kit, would scratch everything else? Talc Diamond Topaz Calcite How comfortable and confident do you feel about your overall understanding and use of the scratch tests and the Mohs hardness scale? Very comfortable and confident Comfortable and confident Not comfortable and confident Really not comfortable and confident