Answer:
Obsidian- Extrusive igneous
Granite- Intrusive igneous
Conglomerate- Clastic sedimentary
Evaporite- Chemical sedimentary
Coal- Organic sedimentary
Marble- Metamorphic
Explanation:
1) Obsidian- This rocks are volcanic glasses formed naturally because of a felsic volcanic eruption. They are generally blackish in color and are found on the earth's surface, considered as an extrusive volcanic igneous rock.
2) Granite- This rocks are formed when hot intrusive magma undergoes crystallization under the earth's surface. The minerals are coarser due to the slow rate of cooling.
3) Conglomerate- It is a clastic sedimentary rock which is comprised of comparatively larger and circular rock fragments and these fragments are attached to one another with quartz or calcitic cements, that makes the rock hard.
4) Evaporite- This are formed when the water evaporates precipitating a certain type of mineral deposit such as the natural salt. They are considered as the chemical sedimentary rock.
5) Coal- It is an organic sedimentary rock that is formed from the ancient fossilized plants that were buried millions of years ago. They are very dark in color and are widely used to produce electricity. They are comprised of carbon compound.
6) Marble- It is a metamorphic rock, formed when calcite or dolomite rock undergoes changes due to the increasing temperature and pressure conditions.