Question

diorite forms from melted rock. dolerite can form when melted rock cools below the earths surface. this piece of diorite has white and black mineral grains in it. diorite is a very hard rock. the people of ancient egypt used diorite to make pottery and sculptures. diorite was also used to polish other rocks such as granite. what type of rock is diorite? metamorphic igneous sedimentary

Explanation:

文中提到闪长岩（diorite）由熔化的岩石形成，这符合火成岩（igneous rock）的形成特征，火成岩是由岩浆冷却凝固形成的。变质岩（metamorphic rock）是原有的岩石在高温高压等条件下发生变质作用形成；沉积岩（sedimentary rock）是由沉积物经过压实、胶结等作用形成。

Answer:

B. igneous