Mineral Hardness: Mohs Scale

What does hardness in minerals primarily measure?

Which of the following objects can be used to test the hardness of a mineral?

A mineral that scores 6.5 on Mohs Scale is classified as:

How is tenacity defined in relation to minerals?

Which term describes a mineral that bends but returns to its original shape?

Which statement about diamond is true?

Which property is NOT used to classify minerals?

In geological terms, what are rock-forming minerals?

Which of the following is NOT a native mineral as defined in the text?

What is the chemical formula for olivine, a silicate mineral mentioned in the text?

Which of the following elements is NOT a common cation found in silicate minerals?

What is the main difference between native minerals and silicate minerals?

Which of the following is an example of an oxide mineral?

What is the chemical formula for quartz, a pure form of silicon dioxide?

What is the significance of industrial minerals?

Which of the following minerals is NOT mentioned as an example of an oxide mineral in the text?

Measures mineral resistance to scratching
A harder substance will scratch a softer one
Mohs Scale of Hardness is widely used by geologists and engineers to distinguish between hard and soft minerals
Hard minerals: scratch glass, cannot be scratched with a knife blade or masonry nail
Soft minerals: do not scratch glass, can be scratched with a knife blade or masonry nail

Measures resistance of a mineral to breakage
Minerals can be brittle (shatters like glass), elastic (bends but returns to its original shape), or malleable (bent permanently into new shapes)
Examples: gold is malleable, diamond is very brittle

Rock-forming minerals: make up most of Earth’s crust
Industrial minerals: main non-fuel raw materials used to sustain industrialized societies
Classified into chemical classes:
- Native minerals: single-element minerals, elements in pure form, not combined with different elements
- Examples: graphite, copper, sulphur, gold, silver
- Silicate minerals:
  - Predominant group in terms of abundance in crust and mantle
  - Composed of SiO4 Tetrahedrons and Cations: K+, Na+, Ca+2, Mg+2, Fe+2 or Al+3
  - Examples: quartz, olivine, potassium feldspar, kaolinite
- Oxide minerals:
  - Contain oxygen combined with a metal (except for silicates)
  - Examples: hematite, magnetite, corundum