Which of the following is an example of a mineral?

A) water
B) granite
C) coal
D) quartz

quartz

http://www.minerals.net/mineral/silicate/tecto/quartz/quartz.htm

D) quartz

To determine which of the given options is an example of a mineral, we need to understand the characteristics of minerals.

A mineral is a naturally occurring, inorganic solid substance that has a specific chemical composition and a characteristic crystalline structure. It is typically formed through geological processes over millions of years.

Now let's analyze each option:

A) Water: Water is a compound composed of hydrogen and oxygen atoms. While water is essential for life, it does not meet the criteria of being a mineral because it is not an inorganic solid substance and does not possess a crystalline structure.

B) Granite: Granite is an igneous rock composed mainly of minerals such as quartz, feldspar, and mica. While granite contains minerals, it is not considered a mineral itself.

C) Coal: Coal is a sedimentary rock formed from the remains of plant material. While it is derived from organic matter and contains carbon, it is not considered a mineral.

D) Quartz: Quartz, on the other hand, is a mineral and fits all the criteria. It is a naturally occurring, inorganic solid substance, with a specific chemical composition (silicon dioxide) and a characteristic crystalline structure. It is one of the most abundant minerals on Earth.

Therefore, the correct answer is D) quartz.