The softest mineral on the Mohs hardness scale is
A. quartz
B. talc
C. apatite
D. gypsum
The Correct Answer and Explanation is :
The correct answer is B. talc.
Talc is the softest mineral on the Mohs hardness scale, with a rating of 1. The Mohs scale of mineral hardness is a qualitative scale that ranks minerals based on their ability to scratch one another. It ranges from 1 (the softest) to 10 (the hardest). The scale was developed by the German mineralogist Friedrich Mohs in 1812.
Talc, with its Mohs hardness of 1, is so soft that it can be easily scratched by almost any other substance. It is a silicate mineral composed primarily of magnesium, silicon, and oxygen. Due to its softness, talc is commonly used in products like baby powder, cosmetics, and as a lubricant in some industrial applications. It is often found in metamorphic rocks and has a greasy or soapy feel.
Here’s a comparison with the other minerals mentioned:
- A. Quartz: Quartz is much harder than talc, with a Mohs hardness of 7. It can scratch most other minerals and is commonly used in the manufacture of glass and as an abrasive material.
- C. Apatite: Apatite has a Mohs hardness of 5. It is a group of phosphate minerals and is harder than both talc and gypsum. It is the mineral from which phosphorus is extracted for fertilizers.
- D. Gypsum: Gypsum is softer than quartz and apatite, with a Mohs hardness of 2, but it is still much harder than talc.
In conclusion, talc’s position as the softest mineral on the Mohs scale makes it the correct answer. It is used for various practical purposes due to its softness and unique properties, such as its ability to absorb moisture and reduce friction.