Audio
Mohs Hardness Chart
Transcript
The heading at the top of the chart reads Mohs Hardness Scale. This chart includes three columns. The heading of the left column reads “Mineral Name” and lists different minerals. They are arranged by hardness, decreasing from the top to bottom. The middle column reads “Scale Number” and assigns each mineral a scale number starting with 10 at the top and decreasing to 1 at the bottom. The right column reads “Common Objects” and lists common objects and assigns each of them a hardness number. There is also a small illustration of each common object. The first mineral listed is diamond. It is assigned a scale number of 10, meaning it is the hardest of the minerals listed. The next mineral down is corundum. There is a small photo of it, a small round, orange colored mass that looks like a rock. It is assigned a scale number of 9. The next mineral down on the chart is topaz. It is assigned a scale number of 8. In the right column there is an illustration of a masonry drill bit along with text that reads “Masonry Drill Bit (8.5)”. The next mineral listed is quartz. There is a small photo of a white quartz crystal to the left of the text. It is assigned a scale number of 7. The next mineral down on the chart is orthoclase. It is assigned a scale number of 6. In the right column is an illustration of a steel nail and text that reads “steel nail (6.5)”. The next mineral listed on the chart is apatite. It is assigned a scale number of 5. In the right column is an illustration of a multi-tool knife and text that reads “knife/glass plate (5.5)”. The next mineral listed is fluorite. There is a small photo of it, a blue colored crystal. It is assigned a scale number of 4. The next mineral listed down the chart is calcite. It is assigned a scale number of 3. In the right column is an illustration of an American penny coin. Next to the illustration is text that reads “copper penny (3.5)”. The next mineral listed is gypsum. It is assigned a scale number of 2. In the right column is an illustration of a human fingertip. Next to the illustration is text that reads “fingernail (2.5). The last mineral listed is talc. It is assigned a scale number of 1. There is a small photo of talc, a white, chalky looking mass.
Description
Park Ranger: Geologist Table - Mohs Hardness Chart is used to help determine what type of rock a person has. The geologist at the table explains how to use the chart to complete the Scratch Test worksheet.
Credit
NPS: E. Grunwald
Date Created
04/01/2023
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