Which of the following rocks is least like a mineral?
a.
Granite
b.
Coal
c.
Sandstone
d.
Quartz
b. Coal
The rock that is least like a mineral is b. Coal. While coal is made up of organic matter, minerals are naturally occurring inorganic substances with a specific chemical composition and crystal structure. Therefore, coal is least like a mineral compared to the other options.
To determine which of the following rocks is least like a mineral, we need to understand the differences between rocks and minerals.
A mineral is a naturally occurring inorganic solid with a specific chemical composition and a crystalline structure. It is composed of one or more elements.
On the other hand, a rock is a naturally occurring solid composed of one or more minerals. Rocks are made up of minerals, mineraloids, or organic materials such as coal.
Now, let's evaluate the options:
a. Granite: Granite is a common type of igneous rock composed mainly of quartz, feldspar, and mica. These minerals are naturally occurring inorganic solids, so granite can be considered as a rock made up of minerals.
b. Coal: Coal is an organic sedimentary rock formed from the remains of plants. While it is not composed of minerals, it is still considered a rock.
c. Sandstone: Sandstone is a sedimentary rock composed of sand-sized mineral particles or rock fragments. It is made up of minerals, so it can be considered as a rock made up of minerals.
d. Quartz: Quartz is a mineral and not a rock. It matches the definition of a mineral as it is a naturally occurring inorganic solid with a specific chemical composition and crystalline structure.
Based on the explanations above, the rock least like a mineral is option b: Coal. While it is considered a rock, it does not consist of minerals but rather organic material.