Example 1
How are a mineral and a rock different, and by what properties is a mineral identified?
1A mineral is a uniform solid formed in nature, while a rock is made of several minerals gathered together.
2A mineral is identified by its own properties such as color, hardness, luster, and streak.
▸ Mineral = uniform solid / rock = a gathering of minerals. Identified by color, hardness, luster, and streak
A rock is a gathering of several minerals, and a mineral is identified by color, hardness, luster, and streak.
Example 2
On the Mohs hardness scale, which is harder, quartz (hardness 7) or talc (hardness 1)? And what happens if you scratch talc with quartz?
1On the Mohs scale, the higher the number, the harder the mineral (talc 1 to diamond 10).
2Quartz (7) is harder than talc (1), so scratching talc with quartz leaves a scratch on the talc.
▸ Quartz is harder / quartz scratches the talc
On the Mohs scale a higher number is harder, and a harder mineral scratches a softer one.
Unit-test style
Which statement about minerals and mineral resources is correct?
①A rock is made of only one kind of mineral
②On the Mohs scale, a higher number means a harder mineral
③Diamond is softer than talc
④Mineral resources are unlimited, so there is no need to save them
⑤Iron ore is a non-metallic mineral
▸ ② On the Mohs scale, a higher number means a harder mineral
1On the Mohs scale, a higher hardness number means a harder mineral, so ② is correct.
2A rock is a gathering of several minerals (①), diamond (10) is harder than talc (1) (③), mineral resources are limited and need saving (④), and iron ore is a metallic mineral (⑤).